Pregnancy#Third trimester

File:Anatomia uteri humani gravidi V00001 00000002.tif, Anatomia uteri humani gravidi tabulis illustrata, 1774|alt=Title page from an 18th-century book about pregnancy]]

Associated terms for pregnancy are gravid and parous. Gravidus and gravid come from the Latin word meaning "heavy" and a pregnant female is sometimes referred to as a gravida.{{Cite web |title=definition of gravida |url=http://medical-dictionary.thefreedictionary.com/gravida |access-date=17 January 2008 |publisher=The Free Dictionary}} Gravidity refers to the number of times that a female has been pregnant. Similarly, the term parity is used for the number of times that a female carries a pregnancy to a viable stage.{{Cite web |title=Gravidity and Parity Definitions (Implications in Risk Assessment) |url=https://patient.info/doctor/gravidity-and-parity-definitions-and-their-implications-in-risk-assessment |url-status=live |archive-url=https://web.archive.org/web/20161212152618/http://patient.info/doctor/gravidity-and-parity-definitions-and-their-implications-in-risk-assessment |archive-date=12 December 2016 |website=patient.info }} Twins and other multiple births are counted as one pregnancy and birth.

A woman who has never been pregnant is referred to as a nulligravida. A woman who is (or has been only) pregnant for the first time is referred to as a primigravida,{{cite-TMHP|Primipara}}, page 596. and a woman in subsequent pregnancies as a multigravida or as multiparous.{{Cite web |title=Definition of nulligravida |url=http://medical.merriam-webster.com/medical/nulligravida |archive-url=https://web.archive.org/web/20080908010608/http://medical.merriam-webster.com/medical/nulligravida |archive-date=8 September 2008 |access-date=9 March 2012 |publisher=Merriam-Webster, Incorporated }} Therefore, during a second pregnancy a woman would be described as gravida 2, para 1 and upon live delivery as gravida 2, para 2. In-progress pregnancies, abortions, miscarriages and/or stillbirths account for parity values being less than the gravida number. Women who have never carried a pregnancy more than 20 weeks are referred to as nulliparous.{{Cite web |date=18 November 2000 |title=Nulliparous definition |url=http://www.medterms.com/script/main/art.asp?articlekey=15259 |url-status=live |archive-url=https://web.archive.org/web/20090709225422/http://www.medterms.com/script/main/art.asp?articlekey=15259 |archive-date=9 July 2009 |publisher=MedicineNet, Inc }}

A pregnancy is considered term at 37 weeks of gestation. It is preterm if less than 37 weeks and post-term at or beyond 42 weeks of gestation. The American College of Obstetricians and Gynecologists have recommended further division with early term 37 weeks up to 39 weeks, full term 39 weeks up to 41 weeks, and late term 41 weeks up to 42 weeks.{{Cite web |title=Definition of Term Pregnancy – ACOG |url=https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Definition-of-Term-Pregnancy |access-date=2019-09-27 |website=www.acog.org}} The terms preterm and post-term have largely replaced earlier terms of premature and postmature. Preterm and postterm are defined above, whereas premature and postmature have historical meaning and relate more to the infant's size and state of development rather than to the stage of pregnancy.{{Cite web |title=Definition of Premature birth | work=Medterms |url=http://www.medterms.com/script/main/art.asp?articlekey=11895 |url-status=live |archive-url=https://web.archive.org/web/20090709225826/http://www.medterms.com/script/main/art.asp?articlekey=11895 |archive-date=9 July 2009 |access-date=16 January 2008 |publisher=Medicine.net }}{{Cite encyclopedia |title=Premature Infant |encyclopedia=Disease & Conditions Encyclopedia |publisher=Discovery Communications, LLC. |url=http://health.discovery.com/encyclopedias/illnesses.html?article=2728 |access-date=16 January 2008 |date=22 September 2006 |archive-url=https://web.archive.org/web/20080119213709/http://health.discovery.com/encyclopedias/illnesses.html?article=2728 |archive-date=19 January 2008 |author=Lama Rimawi, MD |url-status=live }}

About 213 million pregnancies occurred in 2012, of which, 190 million (89%) were in the developing world and 23 million (11%) were in the developed world. The number of pregnancies in women aged between 15 and 44 is 133 per 1,000 women.{{cite journal | vauthors = Sedgh G, Singh S, Hussain R | title = Intended and unintended pregnancies worldwide in 2012 and recent trends | journal = Studies in Family Planning | volume = 45 | issue = 3 | pages = 301–314 | date = September 2014 | pmid = 25207494 | pmc = 4727534 | doi = 10.1111/j.1728-4465.2014.00393.x }} About 10% to 15% of recognized pregnancies end in miscarriage.{{Cite book |url=https://books.google.com/books?id=4Sg5sXyiBvkC&pg=PA438 |title=The Johns Hopkins Manual of Gynecology and Obstetrics |date=2012 |publisher=Lippincott Williams & Wilkins |isbn=978-1-4511-4801-5 |edition=4 |page=438 |archive-url=https://web.archive.org/web/20170910181311/https://books.google.com/books?id=4Sg5sXyiBvkC&pg=PA438 |archive-date=10 September 2017 |url-status=live }} In 2016, complications of pregnancy resulted in 230,600 maternal deaths, down from 377,000 deaths in 1990. Common causes include bleeding, infections, hypertensive diseases of pregnancy, obstructed labor, miscarriage, abortion, or ectopic pregnancy. Globally, 44% of pregnancies are unplanned. Over half (56%) of unplanned pregnancies are aborted.{{cite journal | vauthors = Bearak J, Popinchalk A, Alkema L, Sedgh G | title = Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model | journal = The Lancet. Global Health | volume = 6 | issue = 4 | pages = e380–e389 | date = April 2018 | pmid = 29519649 | pmc = 6055480 | doi = 10.1016/S2214-109X(18)30029-9 }} Among unintended pregnancies in the United States, 60% of the women used birth control to some extent during the month pregnancy began.{{Cite book | vauthors = Hurt KJ, Guile MW, Bienstock JL, Fox HE, Wallach EE |url=https://books.google.com/books?id=4Sg5sXyiBvkC&pg=PR232 |title=The Johns Hopkins manual of gynecology and obstetrics |date=2012-03-28 |publisher=Wolters Kluwer Health / Lippincott Williams & Wilkins |isbn=978-1-60547-433-5 |edition=4th |location=Philadelphia |pages=382 }}

{{Main|Signs and symptoms of pregnancy}}

{{Further|Complications of pregnancy}}

File:Melasmablemish.jpg: pigment changes to the face due to pregnancy]]

File:PregnancyinCrossSection.jpg

Each person's pregnancy can be different and many women do not experience all of the common signs and symptoms.{{Cite web |date=2020-12-02 |title=Signs and symptoms of pregnancy |url=https://www.nhs.uk/pregnancy/trying-for-a-baby/signs-and-symptoms-of-pregnancy/ |access-date=2025-01-23 |website=nhs.uk |language=en}} The usual signs and symptoms of pregnancy do not significantly interfere with activities of daily living or pose a health-threat to the mother or baby. Complications during pregnancy can cause other more severe symptoms, such as those associated with anemia.

Early signs and symptoms of pregnancy may include:{{Cite web |date=2022 |title=Early Signs of Pregnancy |url=https://americanpregnancy.org/pregnancy-symptoms/early-signs-of-pregnancy/ |access-date=2025-01-23 |website=American Pregnancy Association |language=en-US}}

• Tiredness or fatigue (one of the most common symptoms)
• Missed period
• Nausea or morning sickness, may or may not include vomiting
• Breast tenderness (common during the first trimester).
• Increased frequency of urination

Other signs and symptoms that some people may experience at different stages of pregnancy:

• Constipation
• Mood swings
• Regurgitation, heartburn, and bloating
• Headaches
• Food cravings and or food aversions
• Light spotting may sometimes be an early sign of pregnancy in some women. It is also called implantation bleeding.
• Pelvic girdle pain
• Back pain
• Darkening of the areolas
• Braxton Hicks contractions. Occasional, irregular, and often painless contractions that occur several times per day.
• Peripheral edema swelling of the lower limbs. Common complaint in advancing pregnancy. Can be caused by inferior vena cava syndrome resulting from compression of the inferior vena cava and pelvic veins by the uterus leading to increased hydrostatic pressure in lower extremities.
• Low blood pressure often caused by compression of both the inferior vena cava and the abdominal aorta (aortocaval compression syndrome).
• Increased urinary frequency. A common complaint, caused by increased intravascular volume, elevated glomerular filtration rate, and compression of the bladder by the expanding uterus.
• Urinary tract infection{{Cite web |last=Merck |title=Urinary tract infections during pregnancy |url=http://www.merckmanuals.com/home/womens_health_issues/pregnancy_complicated_by_disease/urinary_tract_infections_during_pregnancy.html |url-status=live |archive-url=https://web.archive.org/web/20111110140608/http://www.merckmanuals.com/home/womens_health_issues/pregnancy_complicated_by_disease/urinary_tract_infections_during_pregnancy.html |archive-date=10 November 2011 |website=Merck Manual Home Health Handbook }}
• Varicose veins. Common complaint caused by relaxation of the venous smooth muscle and increased intravascular pressure.
• Hemorrhoids (piles). Swollen veins at or inside the anal area. Caused by impaired venous return, straining associated with constipation, or increased intra-abdominal pressure in later pregnancy.{{cite journal | vauthors = Vazquez JC | title = Constipation, haemorrhoids, and heartburn in pregnancy | journal = BMJ Clinical Evidence | volume = 2010 | pages = 1411 | date = August 2010 | pmid = 21418682 | pmc = 3217736 }}
• Stretch marks
• Melasma, also known as the mask of pregnancy, is a discoloration, most often of the face. It usually begins to fade several months after giving birth.

The chronology of pregnancy is, unless otherwise specified, generally given as gestational age, where the starting point is the beginning of the woman's last menstrual period (LMP), or the corresponding age of the gestation as estimated by a more accurate method if available. This model means that the woman is counted as being "pregnant" two weeks before conception and three weeks before implantation. Sometimes, timing may also use the fertilization age, which is the age of the embryo since conception.

{{Main|Gestational age}}

The American Congress of Obstetricians and Gynecologists recommends the following methods to calculate gestational age:[http://www.acog.org/About_ACOG/ACOG_Departments/Patient_Safety_and_Quality_Improvement/~/media/Departments/Patient%20Safety%20and%20Quality%20Improvement/201213IssuesandRationale-GestationalAgeTerm.pdf Obstetric Data Definitions Issues and Rationale for Change – Gestational Age & Term] {{webarchive|url=https://web.archive.org/web/20131106111500/http://www.acog.org/About_ACOG/ACOG_Departments/Patient_Safety_and_Quality_Improvement/~/media/Departments/Patient%20Safety%20and%20Quality%20Improvement/201213IssuesandRationale-GestationalAgeTerm.pdf |date=6 November 2013 }} from Patient Safety and Quality Improvement at American Congress of Obstetricians and Gynecologists. Created November 2012.

• Directly calculating the days since the beginning of the last menstrual period.
• Early obstetric ultrasound, comparing the size of an embryo or fetus to that of a reference group of pregnancies of known gestational age (such as calculated from last menstrual periods), and using the mean gestational age of other embryos or fetuses of the same size. If the gestational age as calculated from an early ultrasound is contradictory to the one calculated directly from the last menstrual period, it is still the one from the early ultrasound that is used for the rest of the pregnancy.
• In case of in vitro fertilization, calculating days since oocyte retrieval or co-incubation and adding 14 days.{{cite journal | vauthors = Tunón K, Eik-Nes SH, Grøttum P, Von Düring V, Kahn JA | title = Gestational age in pregnancies conceived after in vitro fertilization: a comparison between age assessed from oocyte retrieval, crown-rump length and biparietal diameter | journal = Ultrasound in Obstetrics & Gynecology | volume = 15 | issue = 1 | pages = 41–46 | date = January 2000 | pmid = 10776011 | doi = 10.1046/j.1469-0705.2000.00004.x | s2cid = 20029116 | doi-access = free }}

Pregnancy is divided into three trimesters, each lasting for approximately three months. The exact length of each trimester can vary between sources.

{{anchor|First trimester}}{{anchor|Second trimester}}{{anchor|Third trimester}}

• The first trimester begins with the start of gestational age as described above, that is, the beginning of week 1, or 0 weeks + 0 days of gestational age (GA). It ends at week 12 (11 weeks + 6 days of GA) or end of week 14 (13 weeks + 6 days of GA).{{Cite web |title=Pregnancy – the three trimesters |url=https://www.ucsfhealth.org/conditions/pregnancy/trimesters |access-date=2019-11-30 |website=University of California San Francisco}}
• The second trimester is defined as starting, between the beginning of week 13 (12 weeks +0 days of GA) and beginning of week 15 (14 weeks + 0 days of GA). It ends at the end of week 27 (26 weeks + 6 days of GA) or end of week 28 (27 weeks + 6 days of GA).
• The third trimester is defined as starting, between the beginning of week 28 (27 weeks + 0 days of GA) or beginning of week 29 (28 weeks + 0 days of GA). It lasts until childbirth.

File:Pregnancy timeline.png in weeks and months, viability and maturity stages]]

File:Distribution of gestational age at childbirth.jpg at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period.{{cite journal | vauthors = Hoffman CS, Messer LC, Mendola P, Savitz DA, Herring AH, Hartmann KE | title = Comparison of gestational age at birth based on last menstrual period and ultrasound during the first trimester | journal = Paediatric and Perinatal Epidemiology | volume = 22 | issue = 6 | pages = 587–596 | date = November 2008 | pmid = 19000297 | doi = 10.1111/j.1365-3016.2008.00965.x | author-link5 = Amy H. Herring }} Roughly 80% of births occur between 37 and 41 weeks of gestational age.]]

{{Main|Estimated date of delivery}}

Due date estimation basically follows two steps:

• Determination of which time point is to be used as origin for gestational age, as described in the section above.
• Adding the estimated gestational age at childbirth to the above time point. Childbirth on average occurs at a gestational age of 280 days (40 weeks), which is therefore often used as a standard estimation for individual pregnancies.{{cite web |title=Pregnancy week by week |url=https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20045997 |publisher=Mayo Clinic |access-date=8 July 2023 |date=3 June 2022}} However, alternative durations as well as more individualized methods have also been suggested.

The American College of Obstetricians and Gynecologists divides full term into three divisions:{{cite web |title=ement Health IT and Clinical Informatics reVITALize: Obstetrics Data Definitions reVITALize: Obstetrics Data Definitions |url=https://www.acog.org/practice-management/health-it-and-clinical-informatics/revitalize-obstetrics-data-definitions |website=ACOG |access-date=November 27, 2022}}

• Early-term: 37 weeks and 0 days through 38 weeks and 6 days
• Full-term: 39 weeks and 0 days through 40 weeks and 6 days
• Late-term: 41 weeks and 0 days through 41 weeks and 6 days
• Post-term: greater than or equal to 42 weeks and 0 days

Naegele's rule is a standard way of calculating the due date for a pregnancy when assuming a gestational age of 280 days at childbirth. The rule estimates the expected date of delivery (EDD) by adding a year, subtracting three months, and adding seven days to the origin of gestational age. Alternatively there are mobile apps, which essentially always give consistent estimations compared to each other and correct for leap year, while pregnancy wheels made of paper can differ from each other by 7 days and generally do not correct for leap year.{{cite journal | vauthors = Chambliss LR, Clark SL | title = Paper gestational age wheels are generally inaccurate | journal = American Journal of Obstetrics and Gynecology | volume = 210 | issue = 2 | pages = 145.e1–145.e4 | date = February 2014 | pmid = 24036402 | doi = 10.1016/j.ajog.2013.09.013 }}

Furthermore, actual childbirth has only a certain probability of occurring within the limits of the estimated due date. A study of singleton live births came to the result that childbirth has a standard deviation of 14 days when gestational age is estimated by first trimester ultrasound, and 16 days when estimated directly by last menstrual period.

{{Further|Pregnancy over age 50}}

Fertility and fecundity are the respective capacities to fertilize and establish a clinical pregnancy and have a live birth. Infertility is an impaired ability to establish a clinical pregnancy and sterility is the permanent inability to establish a clinical pregnancy.{{cite journal | vauthors = Zegers-Hochschild F, Adamson GD, Dyer S, Racowsky C, de Mouzon J, Sokol R, Rienzi L, Sunde A, Schmidt L, Cooke ID, Simpson JL, van der Poel S | title = The International Glossary on Infertility and Fertility Care, 2017 | journal = Fertility and Sterility | volume = 108 | issue = 3 | pages = 393–406 | date = September 2017 | pmid = 28760517 | doi = 10.1016/j.fertnstert.2017.06.005 | publisher = Elsevier BV | s2cid = 3640374 | doi-access = free }}

The capacity for pregnancy depends on the reproductive system, its development and its variation, as well as on the condition of a person.

Women as well as intersex and transgender people who have a functioning female reproductive system are capable of pregnancy. In some cases, someone might be able to produce fertilizable eggs, but might not have a womb or none that can sufficiently gestate, in which case they might find surrogacy.{{Cite web |date=2021-11-18 |title=Differences in sex development |url=https://www.nhs.uk/conditions/differences-in-sex-development/ |access-date=2022-06-29 |website=nhs.uk}}

{{See also|Human fertilization}}

File:2904 Preembryonic Development-02.jpg

Through an interplay of hormones that includes follicle stimulating hormone that stimulates folliculogenesis and oogenesis creates a mature egg cell, the female gamete. Fertilization is the event where the egg cell fuses with the male gamete, spermatozoon. After the point of fertilization, the fused product of the female and male gamete is referred to as a zygote or fertilized egg. The fusion of female and male gametes usually occurs following the act of sexual intercourse. Pregnancy rates for sexual intercourse are highest during the menstrual cycle time from some 5 days before until 1 to 2 days after ovulation.{{Cite book | vauthors = Weschler T |url=https://archive.org/details/takingchargeofyo00toni |title=Taking Charge of Your Fertility |publisher=HarperCollins |year=2002 |isbn=978-0-06-093764-5 |edition=Revised |location=New York |pages=[https://archive.org/details/takingchargeofyo00toni/page/242 242], 374 |url-access=registration }} Fertilization can also occur by assisted reproductive technology such as artificial insemination and in vitro fertilisation.

Fertilization (conception) is sometimes used as the initiation of pregnancy, with the derived age being termed fertilization age. Fertilization usually occurs about two weeks before the next expected menstrual period.

A third point in time is also considered by some people to be the true beginning of a pregnancy: This is time of implantation, when the future fetus attaches to the lining of the uterus. This is about a week to ten days after fertilization.{{Cite book | vauthors = Berger KS |url= https://books.google.com/books?id=mC_LNMy2rbkC |title=The Developing Person Through the Life Span |publisher=Macmillan |year=2011 |isbn=978-1-4292-3205-0 |page=90 |archive-url=https://web.archive.org/web/20160425172707/https://books.google.com/books?id=mC_LNMy2rbkC |archive-date=25 April 2016 |url-status=live }}

{{Main|Human embryonic development||Prenatal development|Fetus}}

File:HumanEmbryogenesis.svg]]

The sperm and the egg cell, which has been released from one of the female's two ovaries, unite in one of the two fallopian tubes. The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete. Cell division begins approximately 24 to 36 hours after the female and male cells unite. Cell division continues at a rapid rate and the cells then develop into what is known as a blastocyst. The blastocyst arrives at the uterus and attaches to the uterine wall, a process known as implantation.

The development of the mass of cells that will become the infant is called embryogenesis during the first approximately ten weeks of gestation. During this time, cells begin to differentiate into the various body systems. The basic outlines of the organ, body, and nervous systems are established. By the end of the embryonic stage, the beginnings of features such as fingers, eyes, mouth, and ears become visible. Also during this time, there is development of structures important to the support of the embryo, including the placenta and umbilical cord. The placenta connects the developing embryo to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. The umbilical cord is the connecting cord from the embryo or fetus to the placenta.

After about ten weeks of gestational age—which is the same as eight weeks after conception—the embryo becomes known as a fetus.{{Cite web |title=Stages of Development of the Fetus – Women's Health Issues |url=https://www.msdmanuals.com/en-gb/home/women-s-health-issues/normal-pregnancy/stages-of-development-of-the-fetus |access-date=10 July 2020 |website=MSD Manual Consumer Version}} At the beginning of the fetal stage, the risk of miscarriage decreases sharply.

• Lennart Nilsson, A Child is Born 91 (1990): at eight weeks, "the danger of a miscarriage ... diminishes sharply."
• "[http://www.womens-health.co.uk/miscarr.asp Women's Health Information] {{webarchive|url=https://web.archive.org/web/20070430200911/http://www.womens-health.co.uk/miscarr.asp |date=30 April 2007 }}", Hearthstone Communications Limited: "The risk of miscarriage decreases dramatically after the 8th week as the weeks go by." Retrieved 2007-04-22. At this stage, a fetus is about {{Convert|30|mm|1|abbr=in}} in length, the heartbeat is seen via ultrasound, and the fetus makes involuntary motions.{{Cite book | vauthors = Kalverboer AF, Gramsbergen AA |url= https://books.google.com/books?id=FzyPozUyKPkC&pg=RA1-PA416 |title=Handbook of Brain and Behaviour in Human Development |date=1 January 2001 |publisher=Springer |isbn=978-0-7923-6943-1 |page=1 |archive-url=https://web.archive.org/web/20150919073812/https://books.google.com/books?id=FzyPozUyKPkC&pg=RA1-PA416 |archive-date=19 September 2015 |url-status=live }} During continued fetal development, the early body systems, and structures that were established in the embryonic stage continue to develop. Sex organs begin to appear during the third month of gestation. The fetus continues to grow in both weight and length, although the majority of the physical growth occurs in the last weeks of pregnancy.

Electrical brain activity is first detected at the end of week 5 of gestation, but as in brain-dead patients, it is primitive neural activity rather than the beginning of conscious brain activity. Synapses do not begin to form until week 17.{{Cite book |url=https://books.google.com/books?id=m7USFu5Z0lQC&pg=PA142 |title=Neuroethics: defining the issues in theory, practice, and policy |publisher=Oxford University Press |year=2008 |isbn=978-0-19-856721-9 | veditors = Illes J |edition=Repr. |location=Oxford |pages=142 |archive-url=https://web.archive.org/web/20150919015206/https://books.google.com/books?id=m7USFu5Z0lQC&pg=PA142 |archive-date=19 September 2015 |url-status=live }} Neural connections between the sensory cortex and thalamus develop as early as 24 weeks' gestational age, but the first evidence of their function does not occur until around 30 weeks, when minimal consciousness, dreaming, and the ability to feel pain emerges.

• {{Cite book | vauthors = Harley TA |url= https://books.google.com/books?id=3DcTEAAAQBAJ |title=The Science of Consciousness: Waking, Sleeping and Dreaming |date=2021 |publisher=Cambridge University Press |isbn=978-1-107-12528-5 |location=Cambridge, United Kingdom |page=245 |access-date=May 3, 2022}}
• {{cite book | veditors = Cleeremans A, Wilken P, Bayne T |title=The Oxford Companion to Consciousness |date=2009 |publisher=Oxford University Press |location=New York, NY |isbn=978-0-19-856951-0 |page=229 |url=https://books.google.com/books?id=DuTnCwAAQBAJ |access-date=May 3, 2022}}
• {{cite book | veditors = Thompson E, Moscovitch M, Zelazo PD |title=The Cambridge Handbook of Consciousness |date=2007 |publisher=Cambridge University Press |location=Cambridge, United Kingdom |isbn=978-1-139-46406-2 |pages=415–417 |url=https://books.google.com/books?id=o9ZRc6-FDg8C |access-date=May 3, 2022}}

Although the fetus begins to move during the first trimester, it is not until the second trimester that movement, known as quickening, can be felt. This typically happens in the fourth month, more specifically in the 20th to 21st week, or by the 19th week if the woman has been pregnant before. It is common for some women not to feel the fetus move until much later. During the second trimester, when the body size changes, maternity clothes may be worn.

File:6 weeks pregnant.png|Embryo at 4 weeks after fertilization (gestational age of 6 weeks)

File:10 weeks pregnant.png|Fetus at 8 weeks after fertilization (gestational age of 10 weeks)

File:20 weeks pregnant.png|Fetus at 18 weeks after fertilization (gestational age of 20 weeks)

File:40 weeks pregnant.png|Fetus at 38 weeks after fertilization (gestational age of 40 weeks)

File:Month 1.svg|Relative size in 1st month (simplified illustration)

File:Month 3.svg|Relative size in 3rd month (simplified illustration)

File:Month 5.svg|Relative size in 5th month (simplified illustration)

File:Month 9.svg|Relative size in 9th month (simplified illustration)

Image:Bumm 123 lg.jpg expands making up a larger and larger portion of the abdomen. During the final stages of gestation the uterus may drop to a lower position.]]

{{Main|Maternal physiological changes in pregnancy}}

File:Breast changes during pregnancy 1.png

During pregnancy, a woman undergoes many normal physiological changes, including behavioral, cardiovascular, hematologic, metabolic, renal, and respiratory changes. Increases in blood sugar, breathing, and cardiac output are all required. Levels of progesterone and estrogens rise continually throughout pregnancy, suppressing the hypothalamic axis and therefore the menstrual cycle. A full-term pregnancy at an early age (less than 25 years) reduces the risk of breast, ovarian, and endometrial cancer, and the risk declines further with each additional full-term pregnancy.{{Cite web |title=Abortion & Pregnancy Risks |url=http://ldh.la.gov/index.cfm/page/915 |access-date=22 August 2019 |publisher=Louisiana Department of Health}}{{Cite web |date=30 November 2016 |title=Reproductive History and Cancer Risk |url=https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/reproductive-history-fact-sheet#are-any-pregnancy-related-factors-associated-with-a-lower-risk-of-breast-cancer |access-date=23 August 2019 |website=National Cancer Institute}}

File:Pregnancy 26 weeks 1.jpg

The fetus is genetically different from its mother and can therefore be viewed as an unusually successful allograft.{{Cite book |title=Immunology of pregnancy |date=2006 |publisher=Landes Bioscience/Eurekah.com; Springer Science+Business Media |isbn=978-0-387-34944-2 | veditors = Mor G |series=Medical intelligence unit |location=Georgetown, Tex. : New York |pages=1–4 |doi=10.1007/0-387-34944-8 }} The main reason for this success is increased immune tolerance during pregnancy,{{cite journal | vauthors = Williams Z | title = Inducing tolerance to pregnancy | journal = The New England Journal of Medicine | volume = 367 | issue = 12 | pages = 1159–1161 | date = September 2012 | pmid = 22992082 | pmc = 3644969 | doi = 10.1056/NEJMcibr1207279 }} which prevents the mother's body from mounting an immune system response against certain triggers.

During the first trimester, minute ventilation increases by 40 percent.{{cite journal | vauthors = Campbell LA, Klocke RA | title = Implications for the pregnant patient | journal = American Journal of Respiratory and Critical Care Medicine | volume = 163 | issue = 5 | pages = 1051–1054 | date = April 2001 | pmid = 11316633 | doi = 10.1164/ajrccm.163.5.16353 }} The womb will grow to the size of a lemon by eight weeks. Many symptoms and discomforts of pregnancy, such as nausea and tender breasts, appear in the first trimester.{{Cite web |date=2017-12-20 |title=Your baby at 0–8 weeks pregnancy – Pregnancy and baby guide – NHS Choices |url=http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-weeks-4-5-6-7-8.aspx#close |url-status=live |archive-url=https://web.archive.org/web/20131120025033/http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-weeks-4-5-6-7-8.aspx#close |archive-date=20 November 2013 |website=nhs.uk }}

During the second trimester, most women feel more energized and put on weight as the symptoms of morning sickness subside. They begin to feel regular fetal movements, which can become strong and even disruptive.{{citation needed|date=May 2023}}

Braxton Hicks contractions are sporadic uterine contractions that may start around six weeks into a pregnancy; however, they are usually not felt until the second or third trimester.{{Cite book | vauthors = Hennen L, Murray L, Scott J |url=https://books.google.com/books?id=AK60Xmnrm_AC&q=%22Braxton+Hicks+contractions%22&pg=PA294 |title=The BabyCenter Essential Guide to Pregnancy and Birth: Expert Advice and Real-World Wisdom from THE tip Top Pregnancy and Parenting Resource |publisher=Rodale Books |year=2005 |isbn=1-59486-211-7 |location=Emmaus, Penn.}}

Final weight gain takes place during the third trimester; this is the most weight gain throughout the pregnancy. The woman's abdomen will transform in shape as the fetus turns in a downward position ready for birth. The woman's navel will sometimes become convex, "popping" out, due to the expanding abdomen. The uterus, the muscular organ that holds the developing fetus, can expand up to 20 times its normal size during pregnancy.

Head engagement, also called "lightening" or "dropping", occurs as the fetal head descends into a cephalic presentation. While it relieves pressure on the upper abdomen and gives a renewed ease in breathing, it also severely reduces bladder capacity, resulting in a need to void more frequently, and increases pressure on the pelvic floor and the rectum. It is not possible to predict when lightening will occur. In a first pregnancy it may happen a few weeks before the due date, though it may happen later or even not until labor begins, as is typical with subsequent pregnancies.{{Cite web |title=Pregnancy: Dropping (Lightening) |url=https://www.uofmhealth.org/health-library/aa88159#:~:text=At%20the%20end%20of%20the,but%20it%20can%20happen%20earlier. |access-date=June 9, 2021 |website=University of Michigan}}

It is during the third trimester that maternal activity and sleep positions may affect fetal development due to restricted blood flow. For instance, the enlarged uterus may impede blood flow by compressing the vena cava when lying flat, a condition that can be relieved by lying on the left side.{{cite journal | vauthors = Stacey T, Thompson JM, Mitchell EA, Ekeroma AJ, Zuccollo JM, McCowan LM | title = Association between maternal sleep practices and risk of late stillbirth: a case-control study | journal = BMJ | volume = 342 | pages = d3403 | date = June 2011 | pmid = 21673002 | pmc = 3114953 | doi = 10.1136/bmj.d3403 }}

{{Main|Childbirth}}

Childbirth, referred to as labor and delivery in the medical field, is the process whereby an infant is born.

A woman is considered to be in labor when she begins experiencing regular uterine contractions, accompanied by changes of her cervix—primarily effacement and dilation. While childbirth is widely experienced as painful, some women do report painless labors, while others find that concentrating on the birth helps to quicken labor and lessen the sensations. Most births are successful vaginal births, but sometimes complications arise and a woman may undergo a cesarean section.

During the time immediately after birth, both the mother and the baby are hormonally cued to bond, the mother through the release of oxytocin, a hormone also released during breastfeeding. Studies show that skin-to-skin contact between a mother and her newborn immediately after birth is beneficial for both the mother and baby. A review done by the World Health Organization found that skin-to-skin contact between mothers and babies after birth reduces crying, improves mother–infant interaction, and helps mothers to breastfeed successfully. They recommend that neonates be allowed to bond with the mother during their first two hours after birth, the period that they tend to be more alert than in the following hours of early life.{{cite web|url=http://apps.who.int/rhl/newborn/gpcom/en/index.html|title=RHL|website=apps.who.int|archive-url=https://web.archive.org/web/20111227074038/http://apps.who.int/rhl/newborn/gpcom/en/index.html|archive-date=27 December 2011}}

{{Further|Preterm birth|Postterm pregnancy}}

{{anchor|Term}}

In the ideal childbirth, labor begins on its own when a woman is "at term".

Events before completion of 37 weeks are considered preterm. Preterm birth is associated with a range of complications and should be avoided if possible.{{cite journal | vauthors = Saigal S, Doyle LW | title = An overview of mortality and sequelae of preterm birth from infancy to adulthood | journal = Lancet | volume = 371 | issue = 9608 | pages = 261–269 | date = January 2008 | pmid = 18207020 | doi = 10.1016/S0140-6736(08)60136-1 | s2cid = 17256481 }}

Sometimes if a woman's water breaks or she has contractions before 39 weeks, birth is unavoidable. However, spontaneous birth after 37 weeks is considered term and is not associated with the same risks of a preterm birth.{{Cite book |chapter=Chapter 12. Teratology, Teratogens, and Fetotoxic Agents |chapter-url=http://ucsfcat.library.ucsf.edu/record=b2124757~S0 |veditors=Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS |title=William's Obstetrics |date=2014 |publisher=McGraw-Hill Education |isbn=978-0-07-179893-8 |access-date=9 November 2015 |archive-date=31 December 2018 |archive-url=https://web.archive.org/web/20181231154352/http://ucsfcat.library.ucsf.edu/record=b2124757~S0 }} Planned birth before 39 weeks by caesarean section or labor induction, although "at term", results in an increased risk of complications.{{Citation |last=American Congress of Obstetricians and Gynecologists |title=Five Things Physicians and Patients Should Question |date=February 2013 |url=http://www.choosingwisely.org/doctor-patient-lists/american-college-of-obstetricians-and-gynecologists/ |work=Choosing Wisely: an initiative of the ABIM Foundation |archive-url=https://web.archive.org/web/20130901094916/http://www.choosingwisely.org/doctor-patient-lists/american-college-of-obstetricians-and-gynecologists/ |publisher=American Congress of Obstetricians and Gynecologists |access-date=1 August 2013 |archive-date=1 September 2013 |author-link=American Congress of Obstetricians and Gynecologists |url-status=live}}, which cites

• {{Citation | vauthors = Main E, Oshiro B, Chagolla B, Bingham D, Dang-Kilduff L, Kowalewski L |title=Elimination of Non-medically Indicated (Elective) Deliveries Before 39 Weeks Gestational Age |publisher=March of Dimes; California Maternal Quality Care Collaborative; Maternal, Child and Adolescent Health Division; Center for Family Health; California Department of Public Health |url=http://www.cdph.ca.gov/programs/mcah/Documents/MCAH-EliminationOfNon-MedicallyIndicatedDeliveries.pdf |access-date=1 August 2013 |archive-url=https://web.archive.org/web/20121110174951/http://www.cdph.ca.gov/programs/mcah/Documents/MCAH-EliminationOfNon-MedicallyIndicatedDeliveries.pdf |archive-date=10 November 2012 }} This is from factors including underdeveloped lungs of newborns, infection due to underdeveloped immune system, feeding problems due to underdeveloped brain, and jaundice from underdeveloped liver.{{cite web |url=https://www.npr.org/templates/transcript/transcript.php?storyId=138473097 |title=Doctors To Pregnant Women: Wait at Least 39 Weeks |work=All Things Considered |author=Michele Norris |author-link=Michele Norris |access-date=20 August 2011 |date=18 July 2011 |url-status=live |archive-url=https://web.archive.org/web/20110723081827/http://www.npr.org/templates/transcript/transcript.php?storyId=138473097 |archive-date=23 July 2011 }}

Babies born between 39 and 41 weeks' gestation have better outcomes than babies born either before or after this range. This special time period is called "full term". Whenever possible, waiting for labor to begin on its own in this time period is best for the health of the mother and baby. The decision to perform an induction must be made after weighing the risks and benefits, but is safer after 39 weeks.

Events after 42 weeks are considered postterm. When a pregnancy exceeds 42 weeks, the risk of complications for both the woman and the fetus increases significantly.{{Cite web | vauthors = Norwitz ER |title=Postterm Pregnancy (Beyond the Basics) |url=http://www.uptodate.com/contents/postterm-pregnancy-beyond-the-basics |url-status=live |archive-url=https://web.archive.org/web/20121007020439/http://www.uptodate.com/contents/postterm-pregnancy-beyond-the-basics |archive-date=7 October 2012 |access-date=24 August 2012 |publisher=UpToDate, Inc. }}{{Cite web |last=The American College of Obstetricians and Gynecologists |date=April 2006 |title=What To Expect After Your Due Date |url=http://www.medem.com/MedLB/article_detaillb.cfm?article_ID=ZZZRDLPH97C&sub_cat=2005 |archive-url=https://web.archive.org/web/20030429020622/http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZRDLPH97C&sub_cat=2005 |archive-date=2003-04-29 |access-date=16 January 2008 |website=Medem |publisher=Medem, Inc.}} Therefore, in an otherwise uncomplicated pregnancy, obstetricians usually prefer to induce labor at some stage between 41 and 42 weeks.{{Cite web |year=2001 |title=Induction of labour – Evidence-based Clinical Guideline Number 9 |url=http://www.rcog.org.uk/resources/public/pdf/rcog_induction_of_labour.pdf |archive-url=https://web.archive.org/web/20061230063449/http://www.rcog.org.uk/resources/public/pdf/rcog_induction_of_labour.pdf |archive-date=30 December 2006 |access-date=18 January 2008 |publisher=Royal College of Obstetricians and Gynaecologists}}

{{Main|Postpartum period}}

The postpartum period also referred to as the puerperium, is the postnatal period that begins immediately after delivery and extends for about six weeks. During this period, the mother's body begins the return to pre-pregnancy conditions that includes changes in hormone levels and uterus size.

The beginning of pregnancy may be detected either based on symptoms by the woman herself, or by using pregnancy tests. However, an important condition with serious health implications that is quite common is the denial of pregnancy by the pregnant woman. About 1 in 475 denials will last until around the 20th week of pregnancy. The proportion of cases of denial, persisting until delivery is about 1 in 2500.{{cite journal | vauthors = Jenkins A, Millar S, Robins J | title = Denial of pregnancy: a literature review and discussion of ethical and legal issues | journal = Journal of the Royal Society of Medicine | volume = 104 | issue = 7 | pages = 286–291 | date = July 2011 | pmid = 21725094 | pmc = 3128877 | doi = 10.1258/jrsm.2011.100376 }} Conversely, some non-pregnant women have a very strong belief that they are pregnant along with some of the physical changes. This condition is known as a false pregnancy.{{Cite book | vauthors = Gabbe S |title=Obstetrics: normal and problem pregnancies |date=2012-01-01 |publisher=Elsevier/Saunders |isbn=978-1-4377-1935-2 |edition=6th |location=Philadelphia |page=[https://books.google.com/books?id=-3ufSTqeb6cC&pg=PA1184 1184] }}

{{Further|Signs and symptoms of pregnancy}}

File:Linea nigra.jpg in a woman at 22 weeks pregnant]]

Most pregnant women experience a number of symptoms,{{Cite web |date=11 March 2010 |title=Pregnancy Symptoms |url=http://www.nhs.uk/livewell/sexandyoungpeople/pages/amipregnant.aspx |url-status=live |archive-url=https://web.archive.org/web/20100228005252/http://www.nhs.uk/Livewell/Sexandyoungpeople/Pages/AmIpregnant.aspx |archive-date=28 February 2010 |access-date=11 March 2010 |publisher=National Health Service (NHS) }} which can signify pregnancy. A number of early medical signs are associated with pregnancy.{{Cite web |date=22 February 2007 |title=Early symptoms of pregnancy: What happens right away |url=http://www.mayoclinic.com/health/symptoms-of-pregnancy/PR00102 |url-status=live |archive-url=https://web.archive.org/web/20070914132824/http://www.mayoclinic.com/health/symptoms-of-pregnancy/PR00102 |archive-date=14 September 2007 |access-date=22 August 2007 |publisher=Mayo Clinic }}{{Cite web |title=Pregnancy Symptoms – Early Signs of Pregnancy: American Pregnancy Association |url=http://www.americanpregnancy.org/gettingpregnant/earlypregnancysymptoms.html |url-status=live |archive-url=https://web.archive.org/web/20080115221928/http://www.americanpregnancy.org/gettingpregnant/earlypregnancysymptoms.html |archive-date=15 January 2008 |access-date=16 January 2008 }} These signs include:

• the presence of human chorionic gonadotropin (hCG) in the blood and urine
• missed menstrual period
• implantation bleeding that occurs at implantation of the embryo in the uterus during the third or fourth week after last menstrual period
• increased basal body temperature sustained for over two weeks after ovulation
• Chadwick's sign (bluish discolouration of the cervix, vagina, and vulva)
• Goodell's sign (softening of the vaginal portion of the cervix)
• Hegar's sign (softening of the uterine isthmus)
• Pigmentation of the linea alba, called linea nigra (darkening of the skin in a midline of the abdomen, resulting from hormonal changes, usually appearing around the middle of pregnancy).
• Darkening of the nipples and areolas due to an increase in hormones.{{Cite web |year=2008 |title=Pregnancy video |url=http://sexperienceuk.channel4.com/education/about/pregnancy |url-status=live |archive-url=https://web.archive.org/web/20090123143201/http://sexperienceuk.channel4.com/education/about/pregnancy |archive-date=23 January 2009 |access-date=22 January 2009 |publisher=Channel 4 }}

{{Further|Pregnancy test}}

Pregnancy detection can be accomplished using one or more various pregnancy tests,{{Cite web |date=19 March 2010 |title=NHS Pregnancy Planner |url=http://www.nhs.uk/Planners/Pregnancycareplanner |access-date=19 March 2010 |publisher=National Health Service (NHS) |archive-date=29 August 2021 |archive-url=https://web.archive.org/web/20210829003934/https://www.nhs.uk/pregnancy/ |url-status=dead }} which detect hormones generated by the newly formed placenta, serving as biomarkers of pregnancy.{{Cite book |url=http://ucsfcat.library.ucsf.edu/record=b2263261~S0 |title=Human chorionic gonadotropin (hCG) |date=2015 |publisher=Elsevier |isbn=978-0-12-800821-8 |veditors=Cole LA, Butler SA |edition=2nd |location=Amsterdam |access-date=10 November 2015 |archive-date=26 January 2021 |archive-url=https://web.archive.org/web/20210126052510/http://ucsfcat.library.ucsf.edu/record=b2263261~S0 }} Blood and urine tests can detect pregnancy by 11 and 14 days, respectively, after fertilization.{{cite journal | vauthors = Qasim SM, Callan C, Choe JK | title = The predictive value of an initial serum beta human chorionic gonadotropin level for pregnancy outcome following in vitro fertilization | journal = Journal of Assisted Reproduction and Genetics | volume = 13 | issue = 9 | pages = 705–708 | date = October 1996 | pmid = 8947817 | doi = 10.1007/BF02066422 | s2cid = 36218409 }}{{Cite web |date=2021-10-18 |title=What is HCG? |url=https://americanpregnancy.org/getting-pregnant/hcg-levels/ |access-date=2023-07-23 |website=American Pregnancy Association}} Blood pregnancy tests are more sensitive than urine tests (giving fewer false negatives).{{Cite web |title=BestBets: Serum or Urine beta-hCG? |url=http://www.bestbets.org/bets/bet.php?id=936 |url-status=live |archive-url=https://web.archive.org/web/20081231135953/http://www.bestbets.org/bets/bet.php?id=936 |archive-date=31 December 2008 }} Home pregnancy tests are urine tests, and normally detect a pregnancy 12 to 15 days after fertilization.{{cite journal | vauthors = Cole LA, Khanlian SA, Sutton JM, Davies S, Rayburn WF | title = Accuracy of home pregnancy tests at the time of missed menses | journal = American Journal of Obstetrics and Gynecology | volume = 190 | issue = 1 | pages = 100–105 | date = January 2004 | pmid = 14749643 | doi = 10.1016/j.ajog.2003.08.043 }} A quantitative blood test can determine approximately the date the embryo was fertilized because hCG levels double every 36 to 72 hours before 8 weeks' gestation. A single test of progesterone levels can also help determine how likely a fetus will survive in those with a threatened miscarriage (bleeding in early pregnancy), but only if the ultrasound result was inconclusive.{{cite journal | vauthors = Verhaegen J, Gallos ID, van Mello NM, Abdel-Aziz M, Takwoingi Y, Harb H, Deeks JJ, Mol BW, Coomarasamy A | title = Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding: meta-analysis of cohort studies | journal = BMJ | volume = 345 | pages = e6077 | date = September 2012 | pmid = 23045257 | pmc = 3460254 | doi = 10.1136/bmj.e6077 }}

{{Main|Obstetric ultrasonography}}

Obstetric ultrasonography can detect fetal abnormalities, detect multiple pregnancies, and improve gestational dating at 24 weeks.{{cite journal | vauthors = Whitworth M, Bricker L, Mullan C | title = Ultrasound for fetal assessment in early pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 7 | pages = CD007058 | date = July 2015 | pmid = 26171896 | pmc = 4084925 | doi = 10.1002/14651858.CD007058.pub3 }} The resultant estimated gestational age and due date of the fetus are slightly more accurate than methods based on last menstrual period.{{cite journal | vauthors = Nguyen TH, Larsen T, Engholm G, Møller H | title = Evaluation of ultrasound-estimated date of delivery in 17,450 spontaneous singleton births: do we need to modify Naegele's rule? | journal = Ultrasound in Obstetrics & Gynecology | volume = 14 | issue = 1 | pages = 23–28 | date = July 1999 | pmid = 10461334 | doi = 10.1046/j.1469-0705.1999.14010023.x | s2cid = 30749264 | doi-access = free }} Ultrasound is used to measure the nuchal fold in order to screen for Down syndrome.{{Cite book |title=Current Medical Diagnosis & Treatment 2015 |vauthors=Pyeritz RE |publisher=McGraw-Hill |year=2014}}

[[File:Lifting guidelines during pregnancy - NIOSH.jpg|thumb|upright=1.3|Flowchart showing the recommended weight limits for lifting at work during pregnancy as a function of lifting frequency, weeks of gestation, and the position of the lifted object relative to the lifter's body.{{cite journal | vauthors = Waters TR, MacDonald LA, Hudock SD, Goddard DE | title = Provisional recommended weight limits for manual lifting during pregnancy | journal = Human Factors | volume = 56 | issue = 1 | pages = 203–214 | date = February 2014 | pmid = 24669554 | pmc = 4606868 | doi = 10.1177/0018720813502223 | url = https://www.cdc.gov/niosh/nioshtic-2/20043108.html | url-status = live | archive-url = https://web.archive.org/web/20170401144543/https://www.cdc.gov/niosh/nioshtic-2/20043108.html | archive-date = 1 April 2017 }}{{cite journal | vauthors = MacDonald LA, Waters TR, Napolitano PG, Goddard DE, Ryan MA, Nielsen P, Hudock SD | title = Clinical guidelines for occupational lifting in pregnancy: evidence summary and provisional recommendations | journal = American Journal of Obstetrics and Gynecology | volume = 209 | issue = 2 | pages = 80–88 | date = August 2013 | pmid = 23467051 | pmc = 4552317 | doi = 10.1016/j.ajog.2013.02.047 }}

|alt=An infographic showing a flow chart leading to three diagrams, each showing two human figures depicting different lengths of gestation, with a grid showing weight limits for different locations in front of the body|250x250px]]

{{Main|Prenatal care|pre-conception counseling}}

Pre-conception counseling is care that is provided to a woman or couple to discuss conception, pregnancy, current health issues and recommendations for the period before pregnancy.{{Cite book |vauthors=Lyons P |url=http://ucsfcat.library.ucsf.edu/record=b2282976~S0 |title=Obstetrics in family medicine: a practical guide |date=2015 |publisher=Humana Press |isbn=978-3-319-20077-4 |edition=2nd |series=Current clinical practice |location=Cham, Switzerland |pages=19–28 |access-date=11 November 2015 |archive-date=26 January 2021 |archive-url=https://web.archive.org/web/20210126165622/http://ucsfcat.library.ucsf.edu/record=b2282976~S0 }}

Prenatal medical care is the medical and nursing care recommended for women during pregnancy, time intervals and exact goals of each visit differ by country.{{cite web|title=WHO {{!}} Antenatal care |url=https://www.who.int/gho/maternal_health/reproductive_health/antenatal_care_text/en/ |website=www.who.int |access-date=2015-11-10 |archive-url=https://web.archive.org/web/20151120203220/http://www.who.int/gho/maternal_health/reproductive_health/antenatal_care_text/en/ |archive-date=20 November 2015 }} Women who are high risk have better outcomes if they are seen regularly and frequently by a medical professional than women who are low risk.{{cite journal | vauthors = Dowswell T, Carroli G, Duley L, Gates S, Gülmezoglu AM, Khan-Neelofur D, Piaggio G | title = Alternative versus standard packages of antenatal care for low-risk pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 7 | pages = CD000934 | date = July 2015 | pmid = 26184394 | pmc = 7061257 | doi = 10.1002/14651858.cd000934.pub3 | collaboration = American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women }} A woman can be labeled as high risk for different reasons including previous complications in pregnancy, complications in the current pregnancy, current medical diseases, or social issues.{{cite journal | title = ACOG Committee Opinion No. 343: psychosocial risk factors: perinatal screening and intervention | journal = Obstetrics and Gynecology | volume = 108 | issue = 2 | pages = 469–477 | date = August 2006 | pmid = 16880322 | doi = 10.1097/00006250-200608000-00046 | author1 = American College of Obstetricians Gynecologists Committee on Health Care for Undeserved Women | doi-access = free }}{{cite book |edition=4th |title=The Johns Hopkins manual of gynecology and obstetrics |url=http://ovidsp.ovid.com/ovidweb.cgi?T=JS&NEWS=n&CSC=Y&PAGE=booktext&D=books&AN=01437579$&XPATH=/PG(0) |publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins |date=2011 |location=Philadelphia |isbn=978-1-4511-0913-9 | veditors = Hurt JK }}

The aim of good prenatal care is prevention, early identification, and treatment of any medical complications.{{cite book |title=Prenatal care: effectiveness and implementation |url=http://ucsfcat.library.ucsf.edu/record=b1285675~S0 |publisher=Cambridge University Press |date=1999 |location=Cambridge, UK; New York |isbn=978-0-521-66196-6 |veditors=McCormick MC, Siegel JE |access-date=10 November 2015 |archive-date=6 November 2018 |archive-url=https://web.archive.org/web/20181106190130/http://ucsfcat.library.ucsf.edu/record=b1285675~S0 }} A basic prenatal visit consists of measurement of blood pressure, fundal height, weight and fetal heart rate, checking for symptoms of labor, and guidance for what to expect next.

{{Main|Nutrition and pregnancy}}

Nutrition during pregnancy is important to ensure healthy growth of the fetus. Nutrition during pregnancy is different from the non-pregnant state. There are increased energy requirements and specific micronutrient requirements. Women benefit from education to encourage a balanced energy and protein intake during pregnancy.{{cite journal | vauthors = Ota E, Hori H, Mori R, Tobe-Gai R, Farrar D | title = Antenatal dietary education and supplementation to increase energy and protein intake | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 6 | pages = CD000032 | date = June 2015 | pmid = 26031211 | doi = 10.1002/14651858.CD000032.pub3 }} Some women may need professional medical advice if their diet is affected by medical conditions, food allergies, or specific religious/ ethical beliefs.{{Cite web |date=2015-04-29 |title={{!}} Choose MyPlate |url=http://www.choosemyplate.gov/moms-medical-conditions |url-status=live |archive-url=https://web.archive.org/web/20151117030557/http://www.choosemyplate.gov/moms-medical-conditions |archive-date=17 November 2015 |access-date=2015-11-15 |website=Choose MyPlate }} Further studies are needed to access the effect of dietary advice to prevent gestational diabetes, although low quality evidence suggests some benefit.{{cite journal | vauthors = Tieu J, Shepherd E, Middleton P, Crowther CA | title = Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus | journal = The Cochrane Database of Systematic Reviews | volume = 1 | issue = 1 | pages = CD006674 | date = January 2017 | pmid = 28046205 | pmc = 6464792 | doi = 10.1002/14651858.CD006674.pub3 }} Adequate periconceptional (time before and right after conception) folic acid (also called folate or Vitamin B₉) intake has been shown to decrease the risk of fetal neural tube defects, such as spina bifida.{{cite journal | vauthors = Klusmann A, Heinrich B, Stöpler H, Gärtner J, Mayatepek E, Von Kries R | title = A decreasing rate of neural tube defects following the recommendations for periconceptional folic acid supplementation | journal = Acta Paediatrica | volume = 94 | issue = 11 | pages = 1538–1542 | date = November 2005 | pmid = 16303691 | doi = 10.1080/08035250500340396 | s2cid = 13506877 }} L-methylfolate, the bioavailable form of folate is also considered acceptable to take. L-methylfolate is best used by the 40% to 60% of the population with genetic polymorphisms that reduce or impair conversion of folic acid into its active form.{{Cite journal |last=Greenberg |first=James A |date=2011 |title=Multivitamin Supplementation During Pregnancy: Emphasis on Folic Acid and l-Methylfolate |journal=Reviews in Obstetrics and Gynecology |volume= 4|issue= 3–4|pages=126–127 |pmid=22229066 |pmc=3250974}} The neural tube develops during the first 28 days of pregnancy, a urine pregnancy test is not usually positive until 14 days post-conception, explaining the necessity to guarantee adequate folate intake before conception.{{cite journal | vauthors = Stevenson RE, Allen WP, Pai GS, Best R, Seaver LH, Dean J, Thompson S | title = Decline in prevalence of neural tube defects in a high-risk region of the United States | journal = Pediatrics | volume = 106 | issue = 4 | pages = 677–683 | date = October 2000 | pmid = 11015508 | doi = 10.1542/peds.106.4.677 | s2cid = 39696556 }} Folate is abundant in green leafy vegetables, legumes, and citrus.{{Cite web |title=Folic acid in diet: MedlinePlus Medical Encyclopedia |url=https://www.nlm.nih.gov/medlineplus/ency/article/002408.htm |url-status=live |archive-url=https://web.archive.org/web/20151117022119/https://www.nlm.nih.gov/medlineplus/ency/article/002408.htm |archive-date=17 November 2015 |access-date=2015-11-15 |website=www.nlm.nih.gov }} In the United States and Canada, most wheat products (flour, noodles) are fortified with folic acid.{{cite journal | title = Use of supplements containing folic acid among women of childbearing age--United States, 2007 | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 57 | issue = 1 | pages = 5–8 | date = January 2008 | pmid = 18185493 | author1 = Centers for Disease Control Prevention (CDC) }}

File:Weight gain during pregnancy.jpg

The amount of healthy weight gain during a pregnancy varies.{{Cite journal |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0007502/ |title=Outcomes of Maternal Weight Gain |vauthors=Viswanathan M, Siega-Riz AM, Moos MK |journal=Evidence Report/Technology Assessment |date=May 2008 |series=Evidence Reports/Technology Assessments, No. 168 |publisher=Agency for Healthcare Research and Quality |pages=1–223 |pmc=4781425 |pmid=18620471 |display-authors=etal |access-date=23 June 2013 |archive-url=https://web.archive.org/web/20130528224327/http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0007502/ |archive-date=28 May 2013 |url-status=live |issue=168 }} Weight gain is related to the weight of the baby, the placenta, extra circulatory fluid, larger tissues, and fat and protein stores. Most needed weight gain occurs later in pregnancy.{{Cite web |last=Institute for Quality and Efficiency in Health Care |title=Weight gain in pregnancy |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0005004/ |url-status=live |archive-url=https://web.archive.org/web/20131214112557/http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0005004/ |archive-date=14 December 2013 |access-date=23 June 2013 |website=Fact sheet |date=22 January 2013 |publisher=Institute for Quality and Efficiency in Health Care }}

The Institute of Medicine recommends an overall pregnancy weight gain for those of normal weight (body mass index of 18.5–24.9), of 11.3–15.9 kg (25–35 pounds) having a singleton pregnancy.{{Cite web |title=Weight Gain During Pregnancy: Reexaminging the Guidelines, Report Brief |url=http://iom.edu/Reports/2009/Weight-Gain-During-Pregnancy-Reexamining-the-Guidelines.aspx |archive-url=https://web.archive.org/web/20100810230502/http://www.iom.edu/Reports/2009/Weight-Gain-During-Pregnancy-Reexamining-the-Guidelines.aspx |archive-date=10 August 2010 |access-date=29 July 2010 |website=Institute of Medicine }} Women who are underweight (BMI of less than 18.5), should gain between 12.7 and 18 kg (28–40 lb), while those who are overweight (BMI of 25–29.9) are advised to gain between 6.8 and 11.3 kg (15–25 lb) and those who are obese (BMI ≥ 30) should gain between 5–9 kg (11–20 lb).{{cite journal | title = ACOG Committee opinion no. 548: weight gain during pregnancy | journal = Obstetrics and Gynecology | volume = 121 | issue = 1 | pages = 210–212 | date = January 2013 | pmid = 23262962 | doi = 10.1097/01.AOG.0000425668.87506.4c | author1 = American College of Obstetricians Gynecologists | doi-access = free }} These values reference the expectations for a term pregnancy.

During pregnancy, insufficient or excessive weight gain can compromise the health of the mother and fetus. The most effective intervention for weight gain in underweight women is not clear. Being or becoming overweight in pregnancy increases the risk of complications for mother and fetus, including cesarean section, gestational hypertension, pre-eclampsia, macrosomia and shoulder dystocia. Excessive weight gain can make losing weight after the pregnancy difficult. Some of these complications are risk factors for stroke.{{cite journal | vauthors = Bushnell C, McCullough LD, Awad IA, Chireau MV, Fedder WN, Furie KL, Howard VJ, Lichtman JH, Lisabeth LD, Piña IL, Reeves MJ, Rexrode KM, Saposnik G, Singh V, Towfighi A, Vaccarino V, Walters MR | title = Guidelines for the prevention of stroke in women: a statement for healthcare professionals from the American Heart Association/American Stroke Association | journal = Stroke | volume = 45 | issue = 5 | pages = 1545–1588 | date = May 2014 | pmid = 24503673 | doi = 10.1161/01.str.0000442009.06663.48 | pmc = 10152977 | s2cid = 6297484 | doi-access = free }}

Around 50% of women of childbearing age in developed countries like the United Kingdom are overweight or obese before pregnancy.{{cite journal | vauthors = Thangaratinam S, Rogozińska E, Jolly K, Glinkowski S, Duda W, Borowiack E, Roseboom T, Tomlinson J, Walczak J, Kunz R, Mol BW, Coomarasamy A, Khan KS | title = Interventions to reduce or prevent obesity in pregnant women: a systematic review | journal = Health Technology Assessment | volume = 16 | issue = 31 | pages = iii–iv, 1–191 | date = July 2012 | pmid = 22814301 | pmc = 4781281 | doi = 10.3310/hta16310 | publisher = National Institute for Health and Care Research }} Diet modification is the most effective way to reduce weight gain and associated risks in pregnancy.

{{Main|Pharmaceutical drugs in pregnancy}}

Drugs used during pregnancy can have temporary or permanent effects on the fetus.{{Cite book |vauthors=Briggs GG, Freeman RK |url=http://ucsfcat.library.ucsf.edu/record=b2263003~S0 |title=Drugs in pregnancy and lactation: A Reference Guide to Fetal and Neonatal Risk |date=2015 |publisher=Wolters Kluwer/Lippincott Williams & Wilkins Health |isbn=978-1-4511-9082-3 |edition=Tenth |location=Philadelphia |page=Appendix |access-date=16 November 2015 |archive-date=25 February 2021 |archive-url=https://web.archive.org/web/20210225185426/http://ucsfcat.library.ucsf.edu/record=b2263003~S0 }} Anything (including drugs) that can cause permanent deformities in the fetus are labeled as teratogens.{{Cite book |last1=Genetic Alliance |last2=The New England Public Health Genetics Education Collaborative |title=Understanding Genetics: A New England Guide for Patients and Health Professionals |date=2010-02-17 |publisher=Genetic Alliance |chapter=Appendix A: Teratogens/Prenatal Substance Abuse |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK132176/}} In the U.S., drugs were classified into categories A, B, C, D and X based on the Food and Drug Administration (FDA) rating system to provide therapeutic guidance based on potential benefits and fetal risks.{{Cite web |title=Press Announcements – FDA issues final rule on changes to pregnancy and lactation labeling information for prescription drug and biological products |url=https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm425317.htm |url-status=live |archive-url=https://web.archive.org/web/20151117040840/https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm425317.htm |archive-date=17 November 2015 |access-date=2015-11-16 |website=www.fda.gov }} Drugs, including some multivitamins, that have demonstrated no fetal risks after controlled studies in humans are classified as Category A. On the other hand, drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X.

{{See also|Neonatal withdrawal}}

The use of recreational drugs in pregnancy can cause various pregnancy complications.

• Alcoholic drinks consumed during pregnancy can cause one or more fetal alcohol spectrum disorders. According to the CDC, there is no known safe amount of alcohol during pregnancy and no safe time to drink during pregnancy, including before a woman knows that she is pregnant.{{Cite web |title=Basics about FASDs |url=https://www.cdc.gov/ncbddd/fasd/facts.html |access-date=25 July 2018 |website=CDC}}
• Tobacco smoking during pregnancy can cause a wide range of behavioral, neurological, and physical difficulties.{{cite journal | vauthors = Hackshaw A, Rodeck C, Boniface S | title = Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls | journal = Human Reproduction Update | volume = 17 | issue = 5 | pages = 589–604 | date = Sep–Oct 2011 | pmid = 21747128 | pmc = 3156888 | doi = 10.1093/humupd/dmr022 }} Smoking during pregnancy causes twice the risk of premature rupture of membranes, placental abruption and placenta previa.Centers for Disease Control and Prevention. 2007. [https://www.cdc.gov/nccdphp/publications/factsheets/prevention/pdf/smoking.pdf Preventing Smoking and Exposure to Secondhand Smoke Before, During, and After Pregnancy] {{webarchive|url=https://web.archive.org/web/20110911020755/http://www.cdc.gov/nccdphp/publications/factsheets/Prevention/pdf/smoking.pdf |date=11 September 2011 }}. Smoking is associated with 30% higher odds of preterm birth.{{cite web|url=https://www.cdc.gov/reproductivehealth/tobaccousepregnancy/index.htm|title=Tobacco Use and Pregnancy – Reproductive Health|website=www.cdc.gov|url-status=live|archive-url=https://web.archive.org/web/20170729151248/https://www.cdc.gov/reproductivehealth/tobaccoUsePregnancy/index.htm|archive-date=29 July 2017|date=2019-01-16}}
• Prenatal cocaine exposure is associated with premature birth, birth defects and attention deficit disorder.
• Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities.{{cite web|title=New Mother Fact Sheet: Methamphetamine Use During Pregnancy|url=http://www.ndmch.com|work=North Dakota Department of Health|access-date=7 October 2011|archive-url=https://web.archive.org/web/20110910221317/http://www.ndmch.com/|archive-date=10 September 2011}} Short-term neonatal outcomes in methamphetamine babies show small deficits in infant neurobehavioral function and growth restriction.{{cite journal | vauthors = Della Grotta S, LaGasse LL, Arria AM, Derauf C, Grant P, Smith LM, Shah R, Huestis M, Liu J, Lester BM | title = Patterns of methamphetamine use during pregnancy: results from the Infant Development, Environment, and Lifestyle (IDEAL) Study | journal = Maternal and Child Health Journal | volume = 14 | issue = 4 | pages = 519–527 | date = July 2010 | pmid = 19565330 | pmc = 2895902 | doi = 10.1007/s10995-009-0491-0 }} Long-term effects in terms of impaired brain development may also be caused by methamphetamine use.
• Cannabis in pregnancy has been shown to be teratogenic in large doses in animals, but has not shown any teratogenic effects in humans.

{{Further|Environmental toxicants and fetal development}}

File:N95 Respirator Use During Advanced Pregnancy.webm use during advanced pregnancy]]

Intrauterine exposure to environmental toxins in pregnancy has the potential to cause adverse effects on prenatal development, and to cause pregnancy complications. Air pollution has been associated with low birth weight infants.{{cite book |title=Prenatal exposures: psychological and educational consequences for children |doi=10.1007/978-0-387-74398-1 |publisher=Springer |date=2008 |location=New York |isbn=978-0-387-74398-1 | vauthors = Martin R, Dombrowski SC |chapter=12. Air and Water Pollution}} Conditions of particular severity in pregnancy include mercury poisoning and lead poisoning. To minimize exposure to environmental toxins, the American College of Nurse-Midwives recommends: checking whether the home has lead paint, washing all fresh fruits and vegetables thoroughly and buying organic produce, and avoiding cleaning products labeled "toxic" or any product with a warning on the label.{{cite journal | vauthors = Byrne CC | title = Environmental hazards during pregnancy. | journal = Journal of Midwifery and Women's Health | date = 2006 | volume = 1 | issue = 51 | pages = 57–58 | doi = 10.1016/j.jmwh.2005.09.008 | pmid = 16402445 }}

Pregnant women can also be exposed to toxins in the workplace, including airborne particles. The effects of wearing an N95 filtering facepiece respirator are similar for pregnant women as for non-pregnant women, and wearing a respirator for one hour does not affect the fetal heart rate.{{Cite web|url=https://blogs.cdc.gov/niosh-science-blog/2015/06/18/respirators-pregnancy/|title=N95 Respirator Use During Pregnancy – Findings from Recent NIOSH Research {{!}} NIOSH Science Blog {{!}} Blogs {{!}} CDC |website=blogs.cdc.gov |date=18 June 2015 |access-date=2016-11-16|url-status=live|archive-url=https://web.archive.org/web/20161116163329/https://blogs.cdc.gov/niosh-science-blog/2015/06/18/respirators-pregnancy/|archive-date=16 November 2016}}

Pregnant women or those who have recently given birth in the U.S. are more likely to be murdered than to die from obstetric causes. These homicides are a combination of intimate partner violence and firearms. Health authorities have called the violence "a health emergency for pregnant women", but say that pregnancy-related homicides are preventable if healthcare providers identify those women at risk and offer assistance to them.{{Cite web |date=2022-10-21 |title=Homicide leading cause of death for pregnant women in U.S. |url=https://www.hsph.harvard.edu/news/hsph-in-the-news/homicide-leading-cause-of-death-for-pregnant-women-in-u-s/ |access-date=2022-11-08 |website=News |publisher=Harvard T.H. Chan School of Public Health}}{{cite web |title=With homicide a leading cause of maternal death, doctors urged to screen pregnant women for domestic violence |url=https://www.cnn.com/2022/10/20/health/homicide-maternal-mortality-us-editorial/index.html |website=CNN Health |date=20 October 2022 |access-date=November 8, 2022}}{{cite journal | vauthors = Wallace ME | title = Trends in Pregnancy-Associated Homicide, United States, 2020 | journal = American Journal of Public Health | volume = 112 | issue = 9 | pages = 1333–1336 | date = September 2022 | pmid = 35797500 | pmc = 9382166 | doi = 10.2105/AJPH.2022.306937 }}

{{main|Sexual activity during pregnancy}}

Most women can continue to engage in sexual activity, including sexual intercourse, throughout pregnancy.{{cite book |edition=24th |title=Williams Obstetrics |chapter-url=http://ucsfcat.library.ucsf.edu/record=b2124757~S0 |publisher=McGraw-Hill Education |date=2014 |location=New York |veditors=Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS |chapter=Chapter 9: Prenatal Care |isbn=978-0-07-179893-8 |access-date=9 November 2015 |archive-date=31 December 2018 |archive-url=https://web.archive.org/web/20181231154352/http://ucsfcat.library.ucsf.edu/record=b2124757~S0 }} Research suggests that during pregnancy both sexual desire and frequency of sexual relations decrease during the first and third trimester, with a rise during the second trimester.{{Cite journal |vauthors=Bermudez MP, Sanchez AI, Buela-Casal G |year=2001 |title=Influence of the Gestation Period on Sexual Desire |url=http://www.psychologyinspain.com/content/full/2001/2.htm |url-status=live |journal=Psychology in Spain |volume=5 |issue=1 |pages=14–16 |archive-url=https://web.archive.org/web/20120209172230/http://www.psychologyinspain.com/content/full/2001/2.htm |archive-date=9 February 2012 }}{{cite journal | vauthors = Fok WY, Chan LY, Yuen PM | title = Sexual behavior and activity in Chinese pregnant women | journal = Acta Obstetricia et Gynecologica Scandinavica | volume = 84 | issue = 10 | pages = 934–938 | date = October 2005 | pmid = 16167907 | doi = 10.1111/j.0001-6349.2005.00743.x | s2cid = 23075166 | doi-access = free }}{{cite journal | vauthors = Reamy K, White SE, Daniell WC, Le Vine ES | title = Sexuality and pregnancy. A prospective study | journal = The Journal of Reproductive Medicine | volume = 27 | issue = 6 | pages = 321–327 | date = June 1982 | pmid = 7120209 }}{{cite journal | vauthors = Malarewicz A, Szymkiewicz J, Rogala J | title = [Sexuality of pregnant women] | language = pl | journal = Ginekologia Polska | volume = 77 | issue = 9 | pages = 733–739 | date = September 2006 | pmid = 17219804 }} Sex during pregnancy is low-risk except when the healthcare provider advises that sexual intercourse be avoided for particular medical reasons. For a healthy pregnant woman, there is no single safe or right way to have sex during pregnancy.

File:A pregnant woman coming back from farm, joyfully Gisting with a elderly woman in saminaka.jpg, Nigeria]]

Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness.{{cite journal | vauthors = Kramer MS, McDonald SW | title = Aerobic exercise for women during pregnancy | journal = The Cochrane Database of Systematic Reviews | volume = 3 | issue = 3 | pages = CD000180 | date = July 2006 | pmid = 16855953 | pmc = 7043271 | doi = 10.1002/14651858.CD000180.pub2 | veditors = Kramer MS }} Physical exercise during pregnancy appears to decrease the need for C-section{{cite journal | vauthors = Domenjoz I, Kayser B, Boulvain M | title = Effect of physical activity during pregnancy on mode of delivery | journal = American Journal of Obstetrics and Gynecology | volume = 211 | issue = 4 | pages = 401.e1–401.11 | date = October 2014 | pmid = 24631706 | doi = 10.1016/j.ajog.2014.03.030 }} and reduce time in labor,{{Cite journal |last1=Barakat |first1=Ruben |last2=Franco |first2=Evelia |last3=Perales |first3=María |last4=López |first4=Carmina |last5=Mottola |first5=Michelle F. |date=May 2018 |title=Exercise during pregnancy is associated with a shorter duration of labor. A randomized clinical trial |url=https://linkinghub.elsevier.com/retrieve/pii/S0301211518300964 |journal=European Journal of Obstetrics & Gynecology and Reproductive Biology |language=en |volume=224 |pages=33–40 |doi=10.1016/j.ejogrb.2018.03.009|pmid=29529475 }} and even vigorous exercise carries no significant risks to babies{{cite journal | vauthors = Beetham KS, Giles C, Noetel M, Clifton V, Jones JC, Naughton G | title = The effects of vigorous intensity exercise in the third trimester of pregnancy: a systematic review and meta-analysis | journal = BMC Pregnancy and Childbirth | volume = 19 | issue = 1 | pages = 281 | date = August 2019 | pmid = 31391016 | pmc = 6686535 | doi = 10.1186/s12884-019-2441-1| doi-access = free }} while providing significant health benefits to the mother. Studies show that performing light moderate intensity and strength exercises while pregnant does not harm the mother’s cardiovascular system and may limit excessive weight gain.{{Cite journal |last1=Perales |first1=MaríA |last2=Santos-Lozano |first2=Alejandro |last3=Sanchis-Gomar |first3=Fabian |last4=Luaces |first4=MaríA |last5=Pareja-Galeano |first5=Helios |last6=Garatachea |first6=Nuria |last7=Barakat |first7=RubéN |last8=Lucia |first8=Alejandro |date=May 2016 |title=Maternal Cardiac Adaptations to a Physical Exercise Program during Pregnancy |url=https://journals.lww.com/00005768-201605000-00017 |journal=Medicine & Science in Sports & Exercise |language=en |volume=48 |issue=5 |pages=896–906 |doi=10.1249/MSS.0000000000000837 |pmid=26694848 |issn=0195-9131}}{{Additional citation needed|reason=a single primary study is not sufficient here|date=November 2024}}

The American College of Sports and Medicine recommends pregnant women should participate in at least 150 minutes/week of moderate exercise.{{Cite web |title=ACSM Blog |url=https://www.acsm.org/blog-detail/acsm-certified-blog/2019/08/06/fit-pregnancy-guidelines-simple-guide |access-date=2024-11-14 |website=ACSM_CMS}} These forms of exercise should avoid heavy lifting, hot temperatures, and high impact sports. The Clinical Practice Obstetrics Committee of Canada recommends that "All women without contraindications should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle during their pregnancy".{{cite journal | vauthors = Davies GA, Wolfe LA, Mottola MF, MacKinnon C, Arsenault MY, Bartellas E, Cargill Y, Gleason T, Iglesias S, Klein M, Martel MJ, Roggensack A, Wilson K, Gardiner P, Graham T, Haennel R, Hughson R, MacDougall D, McDermott J, Ross R, Tiidus P, Trudeau F | title = Exercise in pregnancy and the postpartum period | journal = Journal of Obstetrics and Gynaecology Canada | volume = 25 | issue = 6 | pages = 516–529 | date = June 2003 | pmid = 12806453 | doi = 10.1016/s1701-2163(16)30313-9 }} Although an upper level of safe exercise intensity has not been established, women who were regular exercisers before pregnancy and who have uncomplicated pregnancies should be able to engage in high intensity exercise programs without a higher risk of prematurity, lower birth weight, or gestational weight gain. In general, participation in a wide range of recreational activities appears to be safe, with the avoidance of those with a high risk of falling such as horseback riding or skiing or those that carry a risk of abdominal trauma, such as soccer or hockey.{{cite journal | vauthors = Artal R, O'Toole M | title = Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period | journal = British Journal of Sports Medicine | volume = 37 | issue = 1 | pages = 6–12; discussion 12 | date = February 2003 | pmid = 12547738 | pmc = 1724598 | doi = 10.1136/bjsm.37.1.6 }}

Bed rest, outside of research studies, is not recommended as there is potential harm and no evidence of benefit.{{cite journal | vauthors = McCall CA, Grimes DA, Lyerly AD | title = "Therapeutic" bed rest in pregnancy: unethical and unsupported by data | journal = Obstetrics and Gynecology | volume = 121 | issue = 6 | pages = 1305–1308 | date = June 2013 | pmid = 23812466 | doi = 10.1097/aog.0b013e318293f12f }}

During pregnancy, women can experience a loss of postural stability, pelvic incontinence, back pain, and fatigue, among other symptoms.{{citation needed|date=November 2024}} Resistance training has been found to reduce pregnancy symptoms and reduce postpartum complications.{{citation needed|date=November 2024}} Provided that women also regularly participate in low-impact training, strength training can improve pelvic girdle pain severity postpartum.{{cite journal |doi=10.1093/ptj/pzad171 |doi-access=free |title=The Impact of Exercising on Pelvic Symptom Severity, Pelvic Floor Muscle Strength, and Diastasis Recti Abdominis After Pregnancy: A Longitudinal Prospective Cohort Study |date=2024 |journal=Physical Therapy |volume=104 |issue=4 |pmid=38109793 |pmc=11021861 | vauthors = Vesting S, Gutke A, Fagevik Olsén M, Rembeck G, Larsson ME }} When incorporating exercises that focus on pelvic muscle strength, they can help reduce pain and stress urinary incontinence.

Engaging in regular exercise and physical activity has been shown to be beneficial during pregnancy. Acute bouts of high intensity interval training can help decrease the risks of health complications associated with pregnancy, maintain a healthy body fat percentage during pregnancy, as well as improve overall well-being.{{Cite journal |last1=Yu |first1=Hongli |last2=Santos-Rocha |first2=Rita |last3=Radzimiński |first3=Łukasz |last4=Jastrzębski |first4=Zbigniew |last5=Bonisławska |first5=Iwona |last6=Szwarc |first6=Andrzej |last7=Szumilewicz |first7=Anna |date=2022-12-11 |title=Effects of 8-Week Online, Supervised High-Intensity Interval Training on the Parameters Related to the Anaerobic Threshold, Body Weight, and Body Composition during Pregnancy: A Randomized Controlled Trial |journal=Nutrients |language=en |volume=14 |issue=24 |pages=5279 |doi=10.3390/nu14245279 |doi-access=free |issn=2072-6643 |pmc=9781372 |pmid=36558438}} Pregnant women who participated in high intensity interval training have been shown to undergo physical improvements in body composition after intervention as well as show general improvement in cardiorespiratory fitness and exercise tolerance. Taking part in this style of exercise, similarly to moderate intensity continuous training, has also been shown to improve glycemic response and insulin sensitivity.{{Cite journal |last1=Wowdzia |first1=Jenna B. |last2=Hazell |first2=Tom J. |last3=Davenport |first3=Margie H. |date=September 2022 |title=Glycemic response to acute high-intensity interval versus moderate-intensity continuous exercise during pregnancy |url=http://dx.doi.org/10.14814/phy2.15454 |journal=Physiological Reports |volume=10 |issue=18 |pages=e15454 |doi=10.14814/phy2.15454 |pmid=36117457 |pmc=9483614 |issn=2051-817X}} There are specific concerns to be avoided with exercise during pregnancy such as overheating, fall-risk, and remaining in a supine position for an extended period of time. Inexperienced individuals new to high-intensity interval training could potentially increase their risk for negative conditions associated with hypertension, such as pre-eclampsia.{{Cite journal |last1=Nagpal |first1=Ts |last2=Everest |first2=C |last3=Goudreau |first3=Ad |last4=Manicks |first4=M |last5=Adamo |first5=Kb |date=March 2021 |title=To HIIT or not to HIIT? The question pregnant women may be searching for online: a descriptive observational study |url=https://journals.sagepub.com/doi/10.1177/1757913920985898 |journal=Perspectives in Public Health |language=en |volume=141 |issue=2 |pages=81–88 |doi=10.1177/1757913920985898 |pmid=33579178 |issn=1757-9139}}

{{main|Pregnancy and sleep}}

It has been suggested that shift work and exposure to bright light at night should be avoided at least during the last trimester of pregnancy to decrease the risk of psychological and behavioral problems in the newborn.{{cite journal | vauthors = Reiter RJ, Tan DX, Korkmaz A, Rosales-Corral SA | title = Melatonin and stable circadian rhythms optimize maternal, placental and fetal physiology | journal = Human Reproduction Update | volume = 20 | issue = 2 | pages = 293–307 | year = 2014 | pmid = 24132226 | doi = 10.1093/humupd/dmt054 | doi-access = free }}

The children of women who had high stress levels during pregnancy are slightly more likely to have externalizing behavioral problems such as impulsivity. The behavioral effect was most pronounced during early childhood.{{cite journal | vauthors = Tung I, Hipwell AE, Grosse P, Battaglia L, Cannova E, English G, Quick AD, Llamas B, Taylor M, Foust JE | title = Prenatal stress and externalizing behaviors in childhood and adolescence: A systematic review and meta-analysis | journal = Psychological Bulletin | date = November 2023 | volume = 150 | issue = 2 | pages = 107–131 | pmid = 37971856 | doi = 10.1037/bul0000407 | pmc = 10932904 | s2cid = 265272043 }}

{{see also|Prenatal dental care}}

The increased levels of progesterone and estrogen during pregnancy make gingivitis more likely; the gums become edematous, red in colour, and tend to bleed.{{Cite web|url=http://jprsolutions.info/files/final-file-5af1b556a7b4b5.85475067.pdf|title=Oral health care during pregnancy: A strategies and considerations|access-date=2 June 2018|archive-date=22 August 2018|archive-url=https://web.archive.org/web/20180822014747/http://jprsolutions.info/files/final-file-5af1b556a7b4b5.85475067.pdf}} Also a pyogenic granuloma or "pregnancy tumor", is commonly seen on the labial surface of the papilla. Lesions can be treated by local debridement or deep incision depending on their size, and by following adequate oral hygiene measures.{{cite journal | vauthors = Jafarzadeh H, Sanatkhani M, Mohtasham N | title = Oral pyogenic granuloma: a review | journal = Journal of Oral Science | volume = 48 | issue = 4 | pages = 167–175 | date = December 2006 | pmid = 17220613 | doi = 10.2334/josnusd.48.167 | doi-access = free }} There have been suggestions that severe periodontitis may increase the risk of having preterm birth and low birth weight; however, a Cochrane review found insufficient evidence to determine if periodontitis can develop adverse birth outcomes.{{cite journal | vauthors = Iheozor-Ejiofor Z, Middleton P, Esposito M, Glenny AM | title = Treating periodontal disease for preventing adverse birth outcomes in pregnant women | journal = The Cochrane Database of Systematic Reviews | volume = 2017 | issue = 6 | pages = CD005297 | date = June 2017 | pmid = 28605006 | pmc = 6481493 | doi = 10.1002/14651858.CD005297.pub3 }}

In low risk pregnancies, most health care providers approve flying until about 36 weeks of gestational age.{{cite book | vauthors = Howland G |title=The Mama Natural Week-by-Week Guide to Pregnancy and Childbirth |date=2017 |publisher=Simon and Schuster |isbn=978-1-5011-4668-8 |page=173 |url=https://books.google.com/books?id=7TCzCwAAQBAJ&pg=PA173}} Most airlines allow pregnant women to fly short distances at less than 36 weeks, and long distances at less than 32 weeks.{{cite book | vauthors = Jarvis S, Stone J, Eddleman K, Duenwald M |title=Pregnancy For Dummies |date=2011 |publisher=John Wiley & Sons |isbn=978-1-119-99706-1 |page=157 |url=https://books.google.com/books?id=YaVwrjpeRZsC&pg=PT57}} Many airlines require a doctor's note that approves flying, especially at over 28 weeks. During flights, the risk of deep vein thrombosis is decreased by getting up and walking occasionally, as well as by avoiding dehydration. The exposure to cosmic radiation is negligible for most travelers. For pregnant women, even the longest intercontinental fight would expose them less than 15% of both the NCRPM and ICRP limit.{{Cite web |title=Air Travel During Pregnancy |url=https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2018/08/air-travel-during-pregnancy |access-date=2023-12-22 |website=www.acog.org}} Full body scanners do not use ionizing radiation, and are safe in pregnancy.{{cite web|url=https://www.tsa.gov/blog/2014/07/22/tsa-travel-tips-pregnant-passengers|title=TSA Travel Tips for Pregnant Passengers|date=2014-07-22|website=Transportation Security Administration|access-date=27 February 2019|archive-date=6 August 2020|archive-url=https://web.archive.org/web/20200806200053/https://www.tsa.gov/blog/2014/07/22/tsa-travel-tips-pregnant-passengers}}

{{Main|Birthing classes and birth plans}}

To prepare for the birth of the baby, health care providers recommend that parents attend antenatal classes during the third trimester of pregnancy. Classes include information about the process of labor and birth and the various kinds of births, including both vaginal and caesarean delivery, the use of forceps, and other interventions that may be needed to safely deliver the infant. Types of pain relief, including relaxation techniques, are discussed. Partners or others who may plan to support a woman during her labor and delivery learn how to assist in the birth.{{citation needed|date=September 2023}}

It is also suggested that a birth plan be written at this time. A birth plan is a written statement that outlines the desires of the mother during labor and delivery of the baby. Discussing the birth plan with the midwife or other care provider gives parents a chance to ask questions and learn more about the process of labour.{{cite web |title=Antenatal classes |url=https://www.nhs.uk/pregnancy/labour-and-birth/preparing-for-the-birth/antenatal-classes/ |website=NHS |date=December 2020 |access-date=November 16, 2022}}

In 1991 the WHO launched the Baby-Friendly Hospital Initiative, a global program that recognizes birthing centers and hospitals that offer optimal levels of care for giving birth. Facilities that have been certified as "Baby Friendly" accept visits from expecting parents to familiarize them with the facility and the staff.{{cite web |title=Promoting baby-friendly hospitals |url=https://www.who.int/activities/promoting-baby-friendly-hospitals |website=World Health Organization |access-date=November 16, 2022}}

{{Main|Complications of pregnancy}}{{See also|High-risk pregnancy}}

Each year, ill health as a result of pregnancy is experienced (sometimes permanently) by more than 20 million women around the world.{{cite web|url=http://www.searo.who.int/EN/Section13/Section36/Section129/Section396_1450.htm|title=Reproductive Health and Research Publications: Making Pregnancy Safer|year=2009|publisher=World Health Organization Regional Office for South-East Asia|access-date=7 December 2009|archive-url=https://web.archive.org/web/20091215230752/http://www.searo.who.int/EN/Section13/Section36/Section129/Section396_1450.htm|archive-date=15 December 2009}} In 2016, complications of pregnancy resulted in 230,600 deaths down from 377,000 deaths in 1990. Common causes include bleeding (72,000), infections (20,000), hypertensive diseases of pregnancy (32,000), obstructed labor (10,000), and pregnancy with abortive outcome (20,000), which includes miscarriage, abortion, and ectopic pregnancy.

The following are some examples of pregnancy complications:

• Pregnancy induced hypertension
• Anemia{{cite web |title=Pregnancy complicated by disease|url=https://www.merckmanuals.com/home/women-s-health-issues/pregnancy-complicated-by-disease/anemia-during-pregnancy|work=Merck Manual, Home Health Handbook|publisher=Merck Sharp & Dohme}}
• Postpartum depression, a common but solvable complication following childbirth that may result from decreased hormonal levels.{{cite journal | vauthors = Stewart DE, Vigod S | title = Postpartum Depression | journal = The New England Journal of Medicine | volume = 375 | issue = 22 | pages = 2177–2186 | date = December 2016 | pmid = 27959754 | doi = 10.1056/nejmcp1607649 }}
• Postpartum psychosis
• Thromboembolic disorders, with an increased risk due to hypercoagulability in pregnancy. These are the leading cause of death in pregnant women in the US.{{cite web|author=Lara A Friel |title=Thromboembolic Disorders During Pregnancy |work=Merck Manuals Consumer Version |url= https://www.merckmanuals.com/home/women-s-health-issues/pregnancy-complicated-by-disease/thromboembolic-disorders-during-pregnancy|publisher=Merck Sharp & Dohme Corp}}
• Pruritic urticarial papules and plaques of pregnancy (PUPPP), a skin disease that develops around the 32nd week. Signs are red plaques, papules, and itchiness around the belly button that then spreads all over the body except for the inside of hands and face.
• Ectopic pregnancy, including abdominal pregnancy, implantation of the embryo outside the uterus
• Hyperemesis gravidarum, excessive nausea and vomiting that is more severe than normal morning sickness.
• Pulmonary embolism, a blood clot that forms in the legs and migrates to the lungs.{{cite book | vauthors = Leveno K | title = Williams Manual of Pregnancy Complications | publisher = McGraw-Hill Medical | location = New York | year = 2013 |chapter=52|pages=323–334| isbn = 978-0-07-176562-6 }}
• Acute fatty liver of pregnancy is a rare complication thought to be brought about by a disruption in the metabolism of fatty acids by mitochondria.

There is also an increased susceptibility and severity of certain infections in pregnancy.

{{Main|Miscarriage|Stillbirth}}

{{See also|Miscarriage and grief}}

Miscarriage is the most common complication of early pregnancy. It is defined as the loss of an embryo or fetus before it is able to survive independently. The most common symptom of miscarriage is vaginal bleeding with or without pain. The miscarriage may be evidenced by a clot-like material passing through and out of the vagina.{{cite web |title=What are the symptoms of pregnancy loss (before 20 weeks of pregnancy)? |url=https://www.nichd.nih.gov/health/topics/pregnancyloss/conditioninfo/symptoms |website=NIH |date=September 2017 |access-date=October 4, 2022}} About 80% of miscarriages occur in the first 12 weeks of pregnancy. The underlying cause in about half of cases involves chromosomal abnormalities.{{cite web |title=Miscarriage Causes |url=https://www.webmd.com/baby/4-common-causes-miscarriage#1 |website=WebMD |access-date=October 6, 2022}}

Stillbirth is defined as fetal death after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. Each year about 21,000 babies are stillborn in the U.S.{{cite web |title=What Is Stillborn |url=https://www.cdc.gov/ncbddd/stillbirth/facts.html |website=CDC |date=29 September 2022 |access-date=October 6, 2022}} Sadness, anxiety, and guilt may occur after a miscarriage or a stillbirth. Emotional support may help with processing the loss.{{cite web |title=Miscarriage |website=NHS|url=https://www.nhs.uk/conditions/miscarriage/|date=9 March 2022}} Fathers may experience grief over the loss as well. A large study found that there is a need to increase the accessibility of support services available for fathers.{{cite journal | vauthors = Obst KL, Due C, Oxlad M, Middleton P | title = Men's grief following pregnancy loss and neonatal loss: a systematic review and emerging theoretical model | journal = BMC Pregnancy and Childbirth | volume = 20 | issue = 1 | pages = 11 | date = January 2020 | pmid = 31918681 | pmc = 6953275 | doi = 10.1186/s12884-019-2677-9 | doi-access = free }}

{{Further|Pre-existing disease in pregnancy}}

A pregnant woman may have a pre-existing disease, which is not directly caused by the pregnancy, but may cause complications to develop that include a potential risk to the pregnancy; or a disease may develop during pregnancy.

• Diabetes mellitus and pregnancy deals with the interactions of diabetes mellitus (not restricted to gestational diabetes) and pregnancy. Risks for the child include miscarriage, growth restriction, growth acceleration, large for gestational age (macrosomia), polyhydramnios (too much amniotic fluid), and birth defects.
• Thyroid disease in pregnancy can, if uncorrected, cause adverse effects on fetal and maternal well-being. The deleterious effects of thyroid dysfunction can also extend beyond pregnancy and delivery to affect neurointellectual development in the early life of the child. Demand for thyroid hormones is increased during pregnancy, which may cause a previously unnoticed thyroid disorder to worsen.
• Untreated celiac disease can cause a miscarriage, intrauterine growth restriction, small for gestational age, low birthweight and preterm birth. Often reproductive disorders are the only manifestation of undiagnosed celiac disease and most cases are not recognized. Complications or failures of pregnancy cannot be explained simply by malabsorption, but by the autoimmune response elicited by the exposure to gluten, which causes damage to the placenta. The gluten-free diet avoids or reduces the risk of developing reproductive disorders in pregnant women with celiac disease.{{cite journal | vauthors = Tersigni C, Castellani R, de Waure C, Fattorossi A, De Spirito M, Gasbarrini A, Scambia G, Di Simone N | title = Celiac disease and reproductive disorders: meta-analysis of epidemiologic associations and potential pathogenic mechanisms | journal = Human Reproduction Update | volume = 20 | issue = 4 | pages = 582–593 | year = 2014 | pmid = 24619876 | doi = 10.1093/humupd/dmu007 | doi-access = free | hdl = 10807/56796 | hdl-access = free }}{{cite journal | vauthors = Saccone G, Berghella V, Sarno L, Maruotti GM, Cetin I, Greco L, Khashan AS, McCarthy F, Martinelli D, Fortunato F, Martinelli P | title = Celiac disease and obstetric complications: a systematic review and metaanalysis | journal = American Journal of Obstetrics and Gynecology | volume = 214 | issue = 2 | pages = 225–234 | date = February 2016 | pmid = 26432464 | doi = 10.1016/j.ajog.2015.09.080 | hdl = 11369/330101 | hdl-access = free }} Also, pregnancy can be a trigger for the development of celiac disease in genetically susceptible women who are consuming gluten.{{cite web|title=The Gluten Connection|url=https://www.canada.ca/en/health-canada/services/food-nutrition/reports-publications/food-safety/celiac-disease-gluten-connection-1.html|publisher=Health Canada|access-date=1 October 2013|url-status=live|archive-url=https://web.archive.org/web/20170705183625/https://www.canada.ca/en/health-canada/services/food-nutrition/reports-publications/food-safety/celiac-disease-gluten-connection-1.html|archive-date=5 July 2017|date=May 2009}}
• Lupus in pregnancy confers an increased rate of fetal death in utero, miscarriage, and of neonatal lupus.
• Hypercoagulability in pregnancy is the propensity of pregnant women to develop thrombosis (blood clots). Pregnancy itself is a factor of hypercoagulability (pregnancy-induced hypercoagulability), as a physiologically adaptive mechanism to prevent postpartum bleeding. However, in combination with an underlying hypercoagulable state, the risk of thrombosis or embolism may become substantial.Page 264 in: {{cite book |author=Gresele, Paolo |title=Platelets in hematologic and cardiovascular disorders: a clinical handbook |publisher=Cambridge University Press |location=Cambridge, UK |year=2008 |isbn=978-0-521-88115-9 }}

{{main|Abortion}}

An abortion is the termination of an embryo or fetus via medical method. It is usually done within the first trimester, sometimes in the second, and rarely in the third. Reasons for pregnancies being undesired are broad.{{cite web | vauthors = Zdanowicz C | title=Women have abortions for many reasons aside from rape and incest. Here are some of them | website=CNN | date=2019-05-21 | url=https://www.cnn.com/2019/05/21/health/women-reasons-abortion-trnd/index.html | access-date=2022-07-02}} Many jurisdictions restrict or prohibit abortion, with rape being the most legally permissible exception.{{cite web | title=Law and Policy Guide: Rape and Incest Exceptions | website=Center for Reproductive Rights | date=2022-01-18 | url=https://reproductiverights.org/maps/worlds-abortion-laws/law-and-policy-guide-rape-and-incest-exceptions/ | access-date=2022-07-02}}

{{Main|Birth control}}

Family planning, as well as the availability and use of contraception, along with increased comprehensive sex education, has enabled many to prevent pregnancies when they are not desired. Schemes and funding to support education and the means to prevent pregnancies when they are not intended have been instrumental and are part of the third of the Sustainable Development Goals (SDGs) advanced by the United Nations.{{cite web | title=SDG Indicator 3.7.1 on Contraceptive Use | website=Population Division | url=https://www.un.org/development/desa/pd/data/sdg-indicator-371-contraceptive-use | access-date=2022-07-03}}

{{Further|Obstetrics}}

{{main|Assisted reproductive technology}}

Modern reproductive medicine offers many forms of assisted reproductive technology for couples who stay childless against their will, such as fertility medication, artificial insemination, in vitro fertilization and surrogacy.

File:Volume rendered CT scan of a pregnancy of 37 weeks of gestational age (smaller).gifning (volume rendered in this case) confers a radiation dose to the developing fetus.]]

File:Pregnancy_Check_Up.jpg. Ultrasound is used to check on the growth and development of the fetus.]]

{{Main|Medical imaging in pregnancy}}

Medical imaging may be indicated in pregnancy because of pregnancy complications, disease, or routine prenatal care. Medical ultrasonography including obstetric ultrasonography, and magnetic resonance imaging (MRI) without contrast agents are not associated with any risk for the mother or the fetus, and are the imaging techniques of choice for pregnant women.{{cite web|url=https://www.acog.org/Resources-And-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Guidelines-for-Diagnostic-Imaging-During-Pregnancy-and-Lactation|title=Guidelines for Diagnostic Imaging During Pregnancy and Lactation|website=American Congress of Obstetricians and Gynecologists|url-status=live|archive-url=https://web.archive.org/web/20170730145349/https://www.acog.org/Resources-And-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Guidelines-for-Diagnostic-Imaging-During-Pregnancy-and-Lactation|archive-date=30 July 2017}} February 2016 Projectional radiography, CT scan and nuclear medicine imaging result in some degree of ionizing radiation exposure, but in most cases the absorbed doses are not associated with harm to the baby. At higher dosages or frequency, effects can include miscarriage, birth defects and intellectual disability.

{{See also|Pregnancy rate|Advanced maternal age}}

About 213 million pregnancies occurred in 2012 of which 190 million were in the developing world and 23 million were in the developed world. This is about 133 pregnancies per 1,000 women aged 15 to 44. About 10% to 15% of recognized pregnancies end in miscarriage. Globally, 44% of pregnancies are unplanned. Over half (56%) of unplanned pregnancies are aborted. In countries where abortion is prohibited, or only carried out in circumstances where the mother's life is at risk, 48% of unplanned pregnancies are aborted illegally. Compared to the rate in countries where abortion is legal, at 69%.

Of pregnancies in 2012, 120 million occurred in Asia, 54 million in Africa, 19 million in Europe, 18 million in Latin America and the Caribbean, 7 million in North America, and 1 million in Oceania. Pregnancy rates are 140 per 1000 women of childbearing age in the developing world and 94 per 1000 in the developed world.

The rate of pregnancy, as well as the ages at which it occurs, differ by country and region. It is influenced by a number of factors, such as cultural, social and religious norms; access to contraception; and rates of education. The total fertility rate (TFR) in 2013 was estimated to be highest in Niger (7.03 children/woman) and lowest in Singapore (0.79 children/woman).{{cite web|url=https://www.cia.gov/library/publications/the-world-factbook/rankorder/2127rank.html|title=The World Factbook|work=cia.gov|archive-url=https://web.archive.org/web/20091028133713/https://www.cia.gov/library/publications/the-world-factbook/rankorder/2127rank.html|archive-date=28 October 2009}}

In Europe, the average childbearing age has been rising continuously for some time. In Western, Northern, and Southern Europe, first-time mothers are on average 26 to 29 years old, up from 23 to 25 years at the start of the 1970s. In a number of European countries (Spain), the mean age of women at first childbirth has crossed the 30-year threshold.

This process is not restricted to Europe. Asia, Japan and the United States are all seeing average age at first birth on the rise, and increasingly the process is spreading to countries in the developing world like China, Turkey and Iran. In the US, the average age of first childbirth was 25.4 in 2010.[https://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_01.pdf National Vital Statistics Reports] {{webarchive|url=https://web.archive.org/web/20170720102442/https://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_01.pdf |date=20 July 2017 }} from Centers for Disease Control and Prevention National Center for Health Statistics. Volume 61, Number 1 August 28, 2012: Births: Final Data for 2010

In the United States and United Kingdom, 40% of pregnancies are unplanned, and between a quarter and half of those unplanned pregnancies were unwanted pregnancies.{{cite news|title=40% of pregnancies 'unplanned'|url=http://news.bbc.co.uk/2/hi/health/3515400.stm|newspaper=BBC News|date=16 March 2004|url-status=live|archive-url=https://web.archive.org/web/20120730160553/http://news.bbc.co.uk/2/hi/health/3515400.stm|archive-date=30 July 2012}}{{cite news| vauthors = Jayson S |title=Unplanned pregnancies in U.S. at 40 percent|url=http://www.physorg.com/news/2011-05-unplanned-pregnancies-percent.html|newspaper=PhysOrg.com|date=20 May 2011|url-status=live|archive-url=https://web.archive.org/web/20120105113426/http://www.physorg.com/news/2011-05-unplanned-pregnancies-percent.html|archive-date=5 January 2012}}

In the US, a woman's educational attainment and her marital status are historically correlated with childbearing: the percentage of women unmarried at the time of first birth drops with increasing educational level. Three studies conducted between 2015 and 2018 indicate a large fraction (~80%) of women without a high school diploma or local equivalent in the US are unmarried at the time of their first birth. By contrast, the same studies indicated fewer women with a bachelor's degree or higher (~24%) have their first child while unmarried. However, this phenomenon also has a strong generational component: a 1996 study found 48.2% of US women without a bachelor's degree had their first child whilst unmarried, and only 4% of women with a bachelor's degree had their first child whilst unmarried. These studies indicate a rising trend for US women of all educational levels to be unmarried at the time of their first birth,{{cite journal | vauthors = Cherlin AJ | title = Rising nonmarital first childbearing among college-educated women: Evidence from three national studies | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 118 | issue = 37 | pages = e2109016118 | date = September 2021 | pmid = 34493673 | pmc = 8449381 | doi = 10.1073/pnas.2109016118 | bibcode = 2021PNAS..11809016C | doi-access = free }} and thus a recent weakening of the correlation between educational attainment, marital status, and childbearing.

{{Further|Reproductive rights|Reproductive justice}}

Many countries have various legal regulations in place to protect pregnant women and their children. Many countries have laws against pregnancy discrimination.{{Cite web |title=Maternity and paternity at work: Law and practice across the world |url=https://www.ilo.org/global/topics/equality-and-discrimination/maternity-protection/publications/maternity-paternity-at-work-2014/lang--en/index.htm |access-date=2022-09-03 |website=International Labour Organization}}

Maternity Protection Convention ensures that pregnant women are exempt from activities such as night shifts or carrying heavy stocks. Maternity leave typically provides paid leave from work during roughly the last trimester of pregnancy and for some time after birth. Notable extreme cases include Norway (8 months with full pay) and the United States (no paid leave at all except in some states).

In the United States, some actions that result in miscarriage or stillbirth, such as beating a pregnant woman, are considered crimes. One law that does so is the federal Unborn Victims of Violence Act. In 2014, the American state of Tennessee passed a law which allows prosecutors to charge a woman with criminal assault if she uses illegal drugs during her pregnancy and her fetus or newborn is harmed as a result.{{cite web |url=http://www.salon.com/2014/04/30/tennessee_just_became_the_first_state_that_will_jail_women_for_their_pregnancy_outcomes/ |title=Tennessee just became the first state that will jail women for their pregnancy outcomes |author=Katie Mcdonough |date=30 April 2014 |work=Salon |access-date=5 May 2014 |url-status=live |archive-url=https://web.archive.org/web/20140505061404/http://www.salon.com/2014/04/30/tennessee_just_became_the_first_state_that_will_jail_women_for_their_pregnancy_outcomes/ |archive-date=5 May 2014 }}

However, protections are not universal. In Singapore, the Employment of Foreign Manpower Act forbids current and former work permit holders from becoming pregnant or giving birth in Singapore without prior permission.{{Cite web|url=https://yaledailynews.com/blog/2021/06/16/when-pregnancy-is-a-crime/|title = NONFICTION: When Pregnancy is a Crime|date = 17 June 2021}}{{Cite web|url=https://sso.agc.gov.sg/SL/EFMA1990-S569-2012?DocDate=20210902#Sc4-|title=Employment of Foreign Manpower (Work Passes) Regulations 2012 - Singapore Statutes Online}} Violation of the Act is punishable by a fine of up to S$10,000 (US${{To USD|10000|Singapore|year=2019|r=-2}}) and deportation,{{Cite web|url=https://sso.agc.gov.sg/Act/EFMA1990?ProvIds=pr25A-#pr25A-|title=Employment of Foreign Manpower Act - Singapore Statutes Online}} and until 2010, their employers would lose their $5,000 security bond.{{cite web |url=https://twc2.org.sg/2011/07/01/employers-will-not-lose-security-bond-if-fdw-gets-pregnant-mom/ |title=Employers will not lose security bond if FDW gets pregnant – MOM |website=twc2.org.sg |date=1 July 2011 |access-date=15 December 2021 }}

{{Main|Teenage pregnancy}}

Teenage pregnancy is also known as adolescent pregnancy. The WHO defines adolescence as the period between the ages of 10 and 19 years.{{cite web |title=Adolescent health |url=https://www.who.int/health-topics/adolescent-health#tab=tab_1 |website=www.who.int}} Adolescents face higher health risks than women who give birth at age 20 to 24 and their infants are at a higher risk for preterm birth, low birth weight, and other severe neonatal conditions. Their children continue to face greater challenges, both behavioral and physical, throughout their lives. Teenage pregnancies are also related to social issues, including social stigma, lower educational levels, and poverty.{{cite web |title=The Adverse Effects of Teen Pregnancy |url=https://youth.gov/youth-topics/pregnancy-prevention/adverse-effects-teen-pregnancy |website=youth.gov |access-date=October 26, 2022}}{{cite web |title=Adolescent pregnancy |url=https://www.who.int/news-room/fact-sheets/detail/adolescent-pregnancy |website=World Health Organization |access-date=October 26, 2022}} Studies show that female adolescents are often in abusive relationships at the time of their conceiving.{{cite journal |vauthors=Bekaert S, SmithBattle L |title=Teen Mothers' Experience of Intimate Partner Violence: A Metasynthesis |journal=ANS. Advances in Nursing Science |volume=39 |issue=3 |pages=272–290 |year=2016 |pmid=27490882 |doi=10.1097/ANS.0000000000000129 |s2cid=10471475 |url=https://openaccess.city.ac.uk/id/eprint/14531/1/2ANS%20IPV%20Bekaert%20and%20SmithBattle.docx}}

Nurse-Family Partnership (NFP) is a non-profit organization operating in the United States and the UK designed to serve the needs of low income young mothers who may have special needs in their first pregnancy. Each mother served is partnered with a registered nurse early in her pregnancy and receives ongoing nurse home visits that continue through her child's second birthday. NFP intervention has been associated with improvements in maternal health, child health, and economic security.{{cite web |title=Nurse-Family Partnership |url=https://evidencebasedprograms.org/programs/nurse-family-partnership/ |website=Social Programs that Work |access-date=December 4, 2022}}{{cite news |title=How Home Visits by Nurses Help Mothers and Children, Especially Boys |work=The New York Times |date=25 July 2017 |url=https://www.nytimes.com/2017/07/25/upshot/how-home-visits-by-nurses-help-mothers-and-children-especially-boys.html |access-date=December 6, 2022| vauthors = Miller CC }}

There are significant racial imbalances in pregnancy and neonatal care systems.{{cite journal |vauthors=Pereira GM, Pimentel VM, Surita FG, Silva AD, Brito LG |title=Perceived racism or racial discrimination and the risk of adverse obstetric outcomes: a systematic review |journal=Sao Paulo Med J |volume=140 |issue=5 |pages=705–718 |date=2022 |pmid=36043663 |pmc=9514866 |doi=10.1590/1516-3180.2021.0505.R1.07042022 |url=}} Midwifery guidance, treatment, and care have been related to better birth outcomes. Diminishing racial inequities in health is an increasingly large public health challenge in the United States. Despite the fact that average rates have decreased, data on neonatal mortality demonstrates that racial disparities have persisted and grown. The death rate for African American babies is nearly double that of white neonates. According to studies, congenital defects, SIDS, preterm birth, and low birth weight are all more common among African American babies.{{cite journal | vauthors = Guerra-Reyes L, Hamilton LJ | title = Racial disparities in birth care: Exploring the perceived role of African-American women providing midwifery care and birth support in the United States | journal = Women and Birth | volume = 30 | issue = 1 | pages = e9–e16 | date = February 2017 | pmid = 27364419 | doi = 10.1016/j.wombi.2016.06.004 }}

Midwifery care has been linked to better birth and postpartum outcomes for both mother and child. It caters to the needs of the woman and provides competent, sympathetic care, and is essential for maternal health improvement. The presence of a doula, or birth assistant, during labor and delivery, has also been associated with improved levels of satisfaction with medical birth care. Providers recognized their profession from a historical standpoint, a link to African origins, the diaspora, and prevailing African American struggles. Providers participated in both direct clinical experience and activist involvement. Advocacy efforts aimed to enhance the number of minority birth attendants and to promote the benefits of woman-centered birth care to neglected areas.

{{Main|Transgender pregnancy}}

Transgender people have experienced significant advances in societal acceptance in recent years{{when|date=April 2025}} leaving many health professionals unprepared to provide quality care. A 2015 report suggests that "numbers of transgender individuals who are seeking family planning, fertility, and pregnancy services could certainly be quite large".

Regardless of prior hormone replacement therapy treatments, the progression of pregnancy and birthing procedures for transgender people who carry pregnancies are typically the same as those of cisgender women.{{cite journal | vauthors = Obedin-Maliver J, Makadon HJ | title = Transgender men and pregnancy | journal = Obstetric Medicine | volume = 9 | issue = 1 | pages = 4–8 | date = March 2016 | pmid = 27030799 | pmc = 4790470 | doi = 10.1177/1753495X15612658 }} However, transgender people may be subjected to discrimination, which can include a variety of negative social, emotional, and medical experiences, as pregnancy is regarded as an exclusively female activity. According to a study by the American College of Obstetricians and Gynecologists, there is a lack of awareness, services, and medical assistance available to pregnant trans men.{{cite journal | vauthors = Light AD, Obedin-Maliver J, Sevelius JM, Kerns JL | title = Transgender men who experienced pregnancy after female-to-male gender transitioning | journal = Obstetrics and Gynecology | volume = 124 | issue = 6 | pages = 1120–1127 | date = December 2014 | pmid = 25415163 | doi = 10.1097/AOG.0000000000000540 | s2cid = 36023275 | url = https://escholarship.org/uc/item/3dz427qw }}

File:Church of the Visitation IMG 0637.JPG: Mary, pregnant with Jesus, visiting pregnant Elizabeth, depicted as a statue at the Church of the Visitation in Ein Karem, Israel]]

In most cultures, pregnant women have a special status in society and receive particularly gentle care. At the same time, they are subject to expectations that may exert great psychological pressure, such as having to produce a son and heir. In many traditional societies, pregnancy must be preceded by marriage, on pain of ostracism of mother and (illegitimate) child.

Overall, pregnancy is accompanied by numerous customs that are often subject to ethnological research, often rooted in traditional medicine or religion. The baby shower is an example of a modern custom. Contrary to common misconception, women historically in the United States were not expected to seclude themselves during pregnancy, as was popularized by Gone With the Wind.{{Cite book |last=Baumgarten |first=Linda |url=https://archive.org/details/whatclothesrevea0000baum/ |title=What Clothes Reveal: The Language of Clothing in Colonial and Federal America |publisher=Colonial Williamsburg |year=2002 |isbn=0879352167 |location=Williamsburg, Virginia |pages=148}}{{Cite news |last=Chrisman-Campbell |first=Kimberly |date=July 12, 2013 |title=Dressing for Two |url=https://slate.com/human-interest/2013/07/kay-goldmans-history-of-maternity-clothes-dressing-modern-maternity-reviewed.html |access-date=June 26, 2024 |work=Slate}}

Pregnancy is an important topic in sociology of the family. The prospective child may preliminarily be placed into numerous social roles. The parents' relationship and the relation between parents and their surroundings are also affected.

A belly cast may be made during pregnancy as a keepsake.

{{Main|Pregnancy in art}}

Images of pregnant women, especially small figurines, were made in traditional cultures in many places and periods, though it is rarely one of the most common types of image. These include ceramic figures from some Pre-Columbian cultures, and a few figures from most of the ancient Mediterranean cultures. Many of these seem to be connected with fertility. Identifying whether such figures are actually meant to show pregnancy is often a problem, as well as understanding their role in the culture concerned.

Among the oldest surviving examples of the depiction of pregnancy are prehistoric figurines found across much of Eurasia and collectively known as Venus figurines. Some of these appear to be pregnant.

Due to the important role of the Mother of God in Christianity, the Western visual arts have a long tradition of depictions of pregnancy, especially in the biblical scene of the Visitation, and devotional images called a Madonna del Parto.{{cite book| vauthors = Rossi TV |title=Mary in western art|year=2005|publisher=In Association with Hudson Hills Press|location=New York|isbn=978-0-9712981-9-4|pages=106|url=https://books.google.com/books?id=qd7EZAFouDgC&q=097129819X+pregnancy&pg=PA106}}

The unhappy scene usually called Diana and Callisto, showing the moment of discovery of Callisto's forbidden pregnancy, is sometimes painted from the Renaissance onwards. Gradually, portraits of pregnant women began to appear, with a particular fashion for "pregnancy portraits" in elite portraiture of the years around 1600.

Pregnancy, and especially pregnancy of unmarried women, is also an important motif in literature. Notable examples include Thomas Hardy's 1891 novel Tess of the d'Urbervilles and Goethe's 1808 play Faust.

• Couvade syndrome
• Cryptic pregnancy
• False pregnancy
• Simulated pregnancy
• Pregnancy-related anxiety

{{Reflist|colwidth=30em|refs=

{{Cite book | vauthors = Womack M |url=https://books.google.com/books?id=DvR53MCGx1YC&q=In+most+cultures,+pregnant+women+have+a+special+status+in+society&pg=PA133 |title=The anthropology of health and healing. |publisher=AltaMira Press |year=2010 |isbn=978-0-7591-1044-1 |location=Plymouth |pages=133 }}

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{{refbegin}}

• {{Cite web |title=Nutrition for the First Trimester of Pregnancy |url=https://www.ideafit.com/personal-training/nutrition-for-the-first-trimester-of-pregnancy/ |access-date=9 December 2013 |publisher=IDEA Health & Fitness Association}}
• {{cite journal | vauthors = Bothwell TH | title = Iron requirements in pregnancy and strategies to meet them | journal = The American Journal of Clinical Nutrition | volume = 72 | issue = 1 Suppl | pages = 257S–264S | date = July 2000 | pmid = 10871591 | doi = 10.1093/ajcn/72.1.257S | doi-access = free }}
• {{Cite journal | vauthors = Stevens J |title=Pregnancy envy and the politics of compensatory masculinities |journal=Politics & Gender |volume=1 |issue=2 |pages=265–296 |doi=10.1017/S1743923X05050087 |date=June 2005 |doi-broken-date=24 December 2024 |citeseerx=10.1.1.485.5791 |s2cid=39231847}}

{{refend}}

{{Commons category|Human pregnancy}}

{{Wikiquote}}

{{Wikivoyage|travelling while pregnant}}

• [https://www.merckmanuals.com/home/women-s-health-issues/pregnancy-complicated-by-disease/overview-of-disease-during-pregnancy Merck Manual Home Health Handbook] – further details on the diseases, disorders, etc., which may complicate pregnancy.
• [https://www.nhs.uk/pregnancy/your-pregnancy-care/ Pregnancy care] – NHS guide to having a baby including preconception, pregnancy, labor, and birth.

{{Medical condition classification and resources

| DiseasesDB = 10545

| ICD10 = [https://icd.who.int/browse10/2019/en#/XV O00-O99], {{ICD10|Z|33||z|30}}, {{ICD10|Z34}}, {{ICD10|Z35}}

| ICD9 = {{ICD9|650}}

| MedlinePlus =002398

| eMedicineSubj =article

| eMedicineTopic =259724

| MeshID =D011247

}}

{{Pregnancy}}

{{Women's health|state=collapsed}}

{{Pathology of pregnancy, childbirth and the puerperium}}

{{Pediatric conditions originating in the perinatal period}}

{{Reproductive health}}

{{Reproductive physiology}}

{{Human development}}

{{Sex}}

{{Human sexuality}}

{{Authority control}}

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