Gestational diabetes#Screening

Gestational diabetes is formally defined as "any degree of glucose intolerance with onset or first recognition during pregnancy".{{Cite journal |vauthors=Metzger BE, Coustan DR |date=August 1998 |title=Summary and recommendations of the Fourth International Workshop-Conference on Gestational Diabetes Mellitus. The Organizing Committee |journal=Diabetes Care |volume=21 |issue=Suppl 2 |pages=B161-7 |pmid=9704245}} And the rest of the issue B1–B167. This definition acknowledges the possibility that a woman may have previously undiagnosed diabetes mellitus or may have developed diabetes coincidentally with pregnancy. Whether symptoms subside after pregnancy is also irrelevant to the diagnosis.{{Cite journal |last=American Diabetes Association |date=January 2004 |title=Gestational diabetes mellitus |journal=Diabetes Care |volume=27 Suppl 1 |issue=Supplement 1 |pages=S88-90 |doi=10.2337/diacare.27.2007.s88 |pmid=14693936 |doi-access=free}}

A woman is diagnosed with gestational diabetes when glucose intolerance continues beyond 24 to 28 weeks of gestation.{{cn|date=January 2025}}

The White classification, named after Priscilla White,{{Cite journal |vauthors=White P |date=November 1949 |title=Pregnancy complicating diabetes |journal=The American Journal of Medicine |volume=7 |issue=5 |pages=609–16 |doi=10.1016/0002-9343(49)90382-4 |pmid=15396063}} who pioneered research on the effect of diabetes types on perinatal outcome, is widely used to assess maternal and fetal risk.{{Cite web |title=Priscilla White - White Classification, Diabetes in Pregnancy |url=http://www.diabetes.co.uk/pioneers/priscilla-white.html |url-status=live |archive-url=https://web.archive.org/web/20170302181036/http://www.diabetes.co.uk/pioneers/priscilla-white.html |archive-date=2017-03-02 |access-date=2017-02-20}} It distinguishes between gestational diabetes (type A) and pregestational diabetes (diabetes that existed prior to pregnancy). These two groups are further subdivided according to their associated risks and management.{{Cite book |title=OBSTETRICS: Normal and Problem Pregnancies |vauthors=Gabbe SG, Niebyl JR, Simpson JL |date=2002 |publisher=Churchill Livingstone |isbn=978-0-443-06572-9 |edition=Fourth |location=New York}}

The two subtypes of gestational diabetes under this classification system are:{{cn|date=January 2025}}

• Type A1: abnormal oral glucose tolerance test (OGTT), but normal blood glucose levels during fasting and two hours after meals; diet modification is sufficient to control glucose levels{{Cite journal |date=August 1993 |title=Class A1 gestational diabetes: a meaningful diagnosis? |url=https://pubmed.ncbi.nlm.nih.gov/8336875/ |journal=Obstetrics and Gynecology |volume=82 |issue=2 |pages=260–265 |issn=0029-7844 |pmid=8336875}}
• Type A2: abnormal OGTT compounded by abnormal glucose levels during fasting or after meals; additional therapy with insulin or other medications is required{{Cite journal |date=July 2001 |title=Gestational diabetes mellitus diagnosed with a 2-h 75-g oral glucose tolerance test and adverse pregnancy outcomes |url=https://pubmed.ncbi.nlm.nih.gov/11423494/ |journal=Diabetes Care |volume=24 |issue=7 |pages=1151–1155 |doi=10.2337/diacare.24.7.1151 |issn=0149-5992 |pmid=11423494}}

Diabetes which existed before pregnancy is also split up into several subtypes under this system:{{medcn|date=October 2016}}

• Type B: onset at age 20 or older and duration of less than 10 years.
• Type C: onset at age 10–19 or duration of 10–19 years.
• Type D: onset before age 10 or duration greater than 20 years.
• Type E: overt diabetes mellitus with calcified pelvic vessels.
• Type F: diabetic nephropathy.
• Type R: proliferative retinopathy.
• Type RF: retinopathy and nephropathy.
• Type H: ischemic heart disease.
• Type T: prior kidney transplant.

An early age of onset or long-standing disease comes with greater risks, hence the first three subtypes.{{medcn|date=October 2016}}

Two other sets of criteria are available for diagnosis of gestational diabetes, both based on blood-sugar levels.{{Cite journal |last=American Diabetes Association |date=January 2017 |title=2. Classification and Diagnosis of Diabetes |journal=Diabetes Care |volume=40 |issue=Suppl 1 |pages=S11–S24 |doi=10.2337/dc17-S005 |pmid=27979889 |doi-access=free}}

Criteria for diagnosis of gestational diabetes, using the 100 gram Glucose Tolerance Test, according to Carpenter and Coustan:{{Cite journal |vauthors=Carpenter MW, Coustan DR |date=December 1982 |title=Criteria for screening tests for gestational diabetes |journal=American Journal of Obstetrics and Gynecology |volume=144 |issue=7 |pages=768–73 |doi=10.1016/0002-9378(82)90349-0 |pmid=7148898}}

• Fasting 95 mg/dl
• 1 hour 180 mg/dl
• 2 hours 155 mg/dl
• 3 hours 140 mg/dl

Criteria for diagnosis of gestational diabetes according to National Diabetes Data Group:{{Cite journal |last=Committee on Practice Bulletins—Obstetrics |date=February 2018 |title=ACOG Practice Bulletin No. 190: Gestational Diabetes Mellitus |journal=Obstetrics and Gynecology |volume=131 |issue=2 |pages=e49–e64 |doi=10.1097/AOG.0000000000002501 |pmid=29370047 }}

• Fasting 105 mg/dl
• 1 hour 190 mg/dl
• 2 hours 165 mg/dl
• 3 hours 145 mg/dl

The third criterion used was endorsed by the Diabetes in Pregnancy Study Group India and approved by the National Health Mission in its Guidelineshttps://nhm.gov.in/New_Updates_2018/NHM_Components/RMNCH_MH_Guidelines/Gestational-Diabetes-Mellitus.pdf {{Bare URL PDF|date=August 2024}}

[https://dipsi.in/guidelines/ DIPSI](Diabetes in Pregnancy Study Group India Guidelines

OGTT is performed in pregnant women by measuring the plasma glucose after 2 hours of fasting or non-fasting after ingesting 75 grams of glucose (Monohydrate Dextrose Anhydrous). The Indian Guidelines (DIPSI Test) are simple for diagnosing gestational diabetes (GDM). They can be done quickly in low-resource settings, where many pregnant women visit for ANC check-ups in a Non-fasting state. A single value of ≥140 mg/dl is diagnostic for Gestational Diabetes Mellitus.{{cn|date=January 2025}}

Guidelines to screen glucose intolerance at appropriate Gestational weeks: Prediction of GDM can be done if 2hr PPBG≥110 mg/dl at 10th week. At the 8th week itself, PPBG needs to be estimated because, in case PPBG is > 110 mg/dl at this week, a grace period of 2 weeks is available to bring it down to PPBG <110 mg/dl at the 10th week with metformin 250 mg twice a day, in addition to Medical Nutritional Therapy (MNT) and exercise.{{cite journal |title=Treatment of Early Gestational Glucose Intolerance |journal=Diabetes Asia Journal |date=30 October 2024 |volume=1 |issue=2 |pages=19–22 |doi=10.62996/daj.30102024 }}

Classical risk factors for developing gestational diabetes are:{{Cite journal |vauthors=Ross G |date=June 2006 |title=Gestational diabetes |journal=Australian Family Physician |volume=35 |issue=6 |pages=392–6 |pmid=16751853}}

• Polycystic ovary syndrome{{Cite journal |vauthors=Toulis KA, Goulis DG, Kolibianakis EM, Venetis CA, Tarlatzis BC, Papadimas I |date=August 2009 |title=Risk of gestational diabetes mellitus in women with polycystic ovary syndrome: a systematic review and a meta-analysis |journal=Fertility and Sterility |volume=92 |issue=2 |pages=667–77 |doi=10.1016/j.fertnstert.2008.06.045 |pmid=18710713 |doi-access=free}}
• A previous diagnosis of gestational diabetes or prediabetes, impaired glucose tolerance, or impaired fasting glycaemia
• A family history revealing a first-degree relative with type 2 diabetes
• Maternal age – a woman's risk factor increases as she gets older (especially for women over 35 years of age).
• Paternal age – one study found that a father's age over 55 years was associated with GD{{Cite journal |author-link4=David K. Stevenson |vauthors=Khandwala YS, Baker VL, Shaw GM, Stevenson DK, Lu Y, Eisenberg ML |date=October 2018 |title=Association of paternal age with perinatal outcomes between 2007 and 2016 in the United States: population based cohort study |journal=BMJ |volume=363 |pages=k4372 |doi=10.1136/bmj.k4372 |pmc=6207919 |pmid=30381468}}
• Ethnicity (those with higher risk factors include African-Americans, Afro-Caribbeans, Native Americans, Hispanics, Pacific Islanders, and people originating from South Asia)
• Being overweight, obese or severely obese increases the risk by a factor of 2.1, 3.6, and 8.6, respectively.{{Cite journal |vauthors=Chu SY, Callaghan WM, Kim SY, Schmid CH, Lau J, England LJ, Dietz PM |date=August 2007 |title=Maternal obesity and risk of gestational diabetes mellitus |journal=Diabetes Care |volume=30 |issue=8 |pages=2070–6 |doi=10.2337/dc06-2559a |pmid=17416786 |doi-access=free}}
• A previous pregnancy which resulted in a child with a macrosomia (high birth weight: >90th centile or >4000 g (8 lbs 12.8 oz))
• Previous poor obstetric history
• Other genetic risk factors: There are at least 10 genes where certain polymorphism are associated with an increased risk of gestational diabetes, most notably TCF7L2.{{Cite journal |vauthors=Zhang C, Bao W, Rong Y, Yang H, Bowers K, Yeung E, Kiely M |year=2013 |title=Genetic variants and the risk of gestational diabetes mellitus: a systematic review |journal=Human Reproduction Update |volume=19 |issue=4 |pages=376–90 |doi=10.1093/humupd/dmt013 |pmc=3682671 |pmid=23690305}} The MTNR1B gene is a common gene that is associated with how the body handles insulin and glucose. When this gene is not working properly, it can lead to less insulin production and higher blood glucose levels.{{cite journal |vauthors=Yahaya TO, Salisu T, Abdulrahman YB, Umar AK |title=Update on the genetic and epigenetic etiology of gestational diabetes mellitus: a review |journal=Egyptian Journal of Medical Human Genetics |date=December 2020 |volume=21 |issue=1 |pages=13 |doi=10.1186/s43042-020-00054-8 |arxiv=2101.07350 |doi-access=free }}

In addition to this, statistics show a double risk of GDM in smokers.{{Cite journal |vauthors=Bjørge T, Tretli S, Engeland A |date=December 2004 |title=Relation of height and body mass index to renal cell carcinoma in two million Norwegian men and women |journal=American Journal of Epidemiology |volume=160 |issue=12 |pages=1168–76 |doi=10.1093/aje/kwh345 |pmid=15583369 |doi-access=free}} Some studies have looked at more controversial potential risk factors, such as short stature.{{Cite journal |vauthors=Ma RM, Lao TT, Ma CL, Liao SJ, Lu YF, Du MY, Xiao H, Zhang L, Yang MH, Xiao X |date=November 2007 |title=Relationship between leg length and gestational diabetes mellitus in Chinese pregnant women |journal=Diabetes Care |volume=30 |issue=11 |pages=2960–1 |doi=10.2337/dc07-0763 |pmid=17666468 |doi-access=free}}

About 40–60% of women with GDM have no demonstrable risk factor; for this reason, many advocate to screen all women.{{Cite book |last=ACOG |author-link=American Congress of Obstetricians and Gynecologists |title=Precis V. An Update on Obstetrics and Gynecology. |date=December 1994 |publisher=ACOG (1994) |isbn=978-0-915473-22-9 |page=170}} Typically, women with GDM exhibit no symptoms (another reason for universal screening), but some women may demonstrate increased thirst, increased urination, fatigue, nausea and vomiting, bladder infection, yeast infections and blurred vision.{{Cite web |date=27 April 2020 |title=Gestational Diabetes |url=https://americanpregnancy.org/healthy-pregnancy/pregnancy-complications/gestational-diabetes-855/ |access-date=14 October 2020 |publisher=American Pregnancy Association}}

Pregnant women with these risk factors may need to undergo an early screening in addition to the routine screening.https://www.uwmedicine.org/sites/stevie/files/2020-11/Gestational-Diabetes-Screening-Strategies%2C-Glycemic-Targets-and-Pharmacologic-Management-OB-Consensus-Conference.pdf {{Bare URL PDF|date=August 2024}}

File:insulin glucose metabolism.jpg and influx of glucose (3), glycogen synthesis (4), glycolysis (5) and fatty acid synthesis (6).]]

The precise mechanisms underlying gestational diabetes remain unknown. The hallmark of GDM is increased insulin resistance. Pregnancy hormones and other factors are thought to interfere with the action of insulin as it binds to the insulin receptor. The interference probably occurs at the level of the cell signaling pathway beyond the insulin receptor.{{cite journal |id={{Gale|A20331127}} |last1=Carr |first1=Darcy Barry |last2=Gabbe |first2=Steven |title=Gestational diabetes: detection, management, and implications |journal=Clinical Diabetes |date=January 1998 |volume=16 |issue=1 |pages=4–12 }} Since insulin promotes the entry of glucose into most cells, insulin resistance prevents glucose from entering the cells properly. As a result, glucose remains in the bloodstream, where glucose levels rise. More insulin is needed to overcome this resistance; about 1.5–2.5 times more insulin is produced than in a normal pregnancy.

Insulin resistance is a normal phenomenon emerging in the second trimester of pregnancy, which in cases of GDM progresses thereafter to levels seen in a non-pregnant woman with type 2 diabetes. It is thought to secure glucose supply to the growing fetus. Women with GDM have an insulin resistance that they cannot compensate for with increased production in the β-cells of the pancreas. Placental hormones, and, to a lesser extent, increased fat deposits during pregnancy, seem to mediate insulin resistance during pregnancy. Cortisol and progesterone are the main culprits, but human placental lactogen, prolactin and estradiol contribute, too. Multivariate stepwise regression analysis reveals that, in combination with other placental hormones, leptin, tumor necrosis factor alpha, and resistin are involved in the decrease in insulin sensitivity occurring during pregnancy, with tumor necrosis factor alpha named as the strongest independent predictor of insulin sensitivity in pregnancy.{{Cite journal |vauthors=Xu J, Zhao YH, Chen YP, Yuan XL, Wang J, Zhu H, Lu CM |date=2014 |title=Maternal circulating concentrations of tumor necrosis factor-alpha, leptin, and adiponectin in gestational diabetes mellitus: a systematic review and meta-analysis |journal=TheScientificWorldJournal |volume=2014 |pages=926932 |doi=10.1155/2014/926932 |pmc=4151523 |pmid=25202741 |doi-access=free}} An inverse correlation with the changes in insulin sensitivity from the time before conception through late gestation accounts for about half of the variance in the decrease in insulin sensitivity during gestation: in other words, low levels or alteration of TNF alpha factors corresponds with a greater chance of, or predisposition to, insulin resistance or sensitivity.{{Cite book |title=Obstetrics normal and problem pregnancies |vauthors=Gabbe SG |date=2012 |publisher=Elsevier/Saunders |isbn=978-1-4557-3395-8 |edition=6th |location=Philadelphia |page=890}}

It is unclear why some women are unable to balance insulin needs and develop GDM; however, several explanations have been given, similar to those in type 2 diabetes: autoimmunity, single gene mutations, obesity, along with other mechanisms.{{Cite journal |vauthors=Buchanan TA, Xiang AH |date=March 2005 |title=Gestational diabetes mellitus |journal=The Journal of Clinical Investigation |volume=115 |issue=3 |pages=485–91 |doi=10.1172/JCI24531 |pmc=1052018 |pmid=15765129}}

Though the clinical presentation of gestational diabetes is well characterized, the biochemical mechanism behind the disease is not well known. One proposed biochemical mechanism involves insulin-producing β-cell adaptation controlled by the HGF/c-MET signaling pathway. β-cell adaptation refers to the change that pancreatic islet cells undergo during pregnancy in response to maternal hormones to compensate for the increased physiological needs of the mother and baby. These changes in the β-cells cause increased insulin secretion due to increased β-cell proliferation.{{Cite journal |vauthors=Sorenson RL, Brelje TC |date=June 1997 |title=Adaptation of islets of Langerhans to pregnancy: beta-cell growth, enhanced insulin secretion and the role of lactogenic hormones |journal=Hormone and Metabolic Research |volume=29 |issue=6 |pages=301–7 |doi=10.1055/s-2007-979040 |pmid=9230352 }}

HGF/c-MET has also been implicated in β-cell regeneration, which suggests that HGF/c-MET may help increase β-cell mass to compensate for insulin needs during pregnancy. Recent studies support that loss of HGF/c-MET signaling results in aberrant β-cell adaptation.{{Cite journal |vauthors=Alvarez-Perez JC, Ernst S, Demirci C, Casinelli GP, Mellado-Gil JM, Rausell-Palamos F, Vasavada RC, Garcia-Ocaña A |date=January 2014 |title=Hepatocyte growth factor/c-Met signaling is required for β-cell regeneration |journal=Diabetes |volume=63 |issue=1 |pages=216–23 |doi=10.2337/db13-0333 |pmc=3868042 |pmid=24089510}}{{Cite journal |vauthors=Demirci C, Ernst S, Alvarez-Perez JC, Rosa T, Valle S, Shridhar V, Casinelli GP, Alonso LC, Vasavada RC, García-Ocana A |date=May 2012 |title=Loss of HGF/c-Met signaling in pancreatic β-cells leads to incomplete maternal β-cell adaptation and gestational diabetes mellitus |journal=Diabetes |volume=61 |issue=5 |pages=1143–52 |doi=10.2337/db11-1154 |pmc=3331762 |pmid=22427375}}

c-MET is a receptor tyrosine kinase (RTK) that is activated by its ligand, hepatocyte growth factor (HGF), and is involved in the activation of several cellular processes. When HGF binds c-MET, the receptor homodimerizes and self-phosphorylates to form an SH2 recognition domain. The downstream pathways activated include common signaling molecules such as RAS and MAPK, which affect cell motility and cell cycle progression.{{Cite journal |vauthors=Organ SL, Tsao MS |date=November 2011 |title=An overview of the c-MET signaling pathway |journal=Therapeutic Advances in Medical Oncology |volume=3 |issue=1 Suppl |pages=S7–S19 |doi=10.1177/1758834011422556 |pmc=3225017 |pmid=22128289}}

Studies have shown that HGF is an important signaling molecule in stress-related situations where more insulin is needed. Pregnancy causes increased insulin resistance and a higher insulin demand. The β-cells must compensate for this by either increasing insulin production or proliferating. If neither of the processes occurs, then markers for gestational diabetes are observed. It has been observed that pregnancy increases HGF levels, showing a correlation that suggests a connection between the signaling pathway and increased insulin needs. When no signaling is present, gestational diabetes is more likely to occur.

The exact mechanism of HGF/c-MET regulated β-cell adaptation is not yet known. Several hypotheses about how the signaling molecules contribute to insulin levels during pregnancy have been proposed. c-MET may interact with FoxM1, a molecule important in the cell cycle, as FOXM1 levels decrease when c-MET is not present. Additionally, c-MET may interact with p27 as the protein levels increase with c-MET is not present. Another hypothesis says that c-MET may control β-cell apoptosis because a lack of c-MET causes increased cell death, but the signaling mechanisms have not been elucidated.

Although the mechanism of HGF/c-MET control of gestational diabetes is not yet well understood, there is a strong correlation between the signaling pathway and the inability to produce an adequate amount of insulin during pregnancy and thus it may be the target for future diabetic therapies.

Because glucose travels across the placenta (through diffusion facilitated by GLUT1 carrier), which is located in the syncytiotrophoblast on both the microvilli and basal membranes, these membranes may be the rate-limiting step in placental glucose transport. There is a two- to three-fold increase in the expression of syncytiotrophoblast glucose transporters with advancing gestation. Finally, the role of GLUT3/GLUT4 transport remains speculative. If the untreated gestational diabetes fetus is exposed to consistently higher glucose levels, this leads to increased fetal levels of insulin (insulin itself cannot cross the placenta). The growth-stimulating effects of insulin can lead to excessive growth and a large body (macrosomia). After birth, the high glucose environment disappears, leaving these newborns with ongoing high insulin production and susceptibility to low blood glucose levels (hypoglycemia).{{Cite journal |vauthors=Kelly L, Evans L, Messenger D |date=May 2005 |title=Controversies around gestational diabetes. Practical information for family doctors |journal=Canadian Family Physician |volume=51 |issue=5 |pages=688–95 |pmc=1472928 |pmid=15934273}}

Several screening and diagnostic tests have been used to look for high levels of glucose in plasma or serum in defined circumstances. One method is a stepwise approach where a suspicious result on a screening test is followed by a diagnostic test. Alternatively, a more involved diagnostic test can be used directly at the first prenatal visit for a woman with a high-risk pregnancy. (for example in those with polycystic ovarian syndrome or acanthosis nigricans).

Non-challenge blood glucose tests involve measuring glucose levels in blood samples without challenging the subject with glucose solutions. A blood glucose level is determined when fasting, two hours after a meal, or at any random time. In contrast, challenge tests involve drinking a glucose solution and measuring glucose concentration thereafter in the blood; in diabetes, they tend to remain high. The glucose solution has a very sweet taste which some women find unpleasant; sometimes, therefore, artificial flavours are added. Some women may experience nausea during the test, and more so with higher glucose levels.{{Cite journal |vauthors=Sievenpiper JL, Jenkins DJ, Josse RG, Vuksan V |date=February 2001 |title=Dilution of the 75-g oral glucose tolerance test improves overall tolerability but not reproducibility in subjects with different body compositions |journal=Diabetes Research and Clinical Practice |volume=51 |issue=2 |pages=87–95 |doi=10.1016/S0168-8227(00)00209-6 |pmid=11165688}}{{Cite journal |vauthors=Reece EA, Holford T, Tuck S, Bargar M, O'Connor T, Hobbins JC |date=January 1987 |title=Screening for gestational diabetes: one-hour carbohydrate tolerance test performed by a virtually tasteless polymer of glucose |journal=American Journal of Obstetrics and Gynecology |volume=156 |issue=1 |pages=132–4 |doi=10.1016/0002-9378(87)90223-7 |pmid=3799747}}

There is currently not enough research to show which way is best at diagnosing gestational diabetes.{{cite journal |last1=Farrar |first1=Diane |last2=Duley |first2=Lelia |last3=Dowswell |first3=Therese |last4=Lawlor |first4=Debbie A |title=Different strategies for diagnosing gestational diabetes to improve maternal and infant health |journal=Cochrane Database of Systematic Reviews |date=23 August 2017 |volume=2017 |issue=8 |pages=CD007122 |doi=10.1002/14651858.CD007122.pub4 |pmid=28832911 |pmc=6483546 }} Routine screening of women with a glucose challenge test may find more women with gestational diabetes than only screening women with risk factors.{{Cite journal |vauthors=Tieu J, McPhee AJ, Crowther CA, Middleton P, Shepherd E |date=August 2017 |title=Screening for gestational diabetes mellitus based on different risk profiles and settings for improving maternal and infant health |journal=The Cochrane Database of Systematic Reviews |volume=2017 |issue=8 |pages=CD007222 |doi=10.1002/14651858.CD007222.pub4 |pmc=6483271 |pmid=28771289}} Hemoglobin A^1c (HbA1c) is not recommended for diagnosing gestational diabetes, as it is a less reliable marker of glycemia during pregnancy than oral glucose tolerance testing (OGTT).{{cite press release |title=HbA1c Can Underestimate Maternal Glycemia During Pregnancy |url=https://advances.massgeneral.org/obgyn/journal.aspx?id=1557 |publisher=Massachusetts General Hospital |date=27 May 2020 }}{{cite journal |last1=Edelson |first1=P Kaitlyn |last2=James |first2=Kaitlyn E |last3=Leong |first3=Aaron |last4=Arenas |first4=Juliana |last5=Cayford |first5=Melody |last6=Callahan |first6=Michael J |last7=Bernstein |first7=Sarah N |last8=Tangren |first8=Jessica Sheehan |last9=Hivert |first9=Marie-France |last10=Higgins |first10=John M |last11=Nathan |first11=David M |last12=Powe |first12=Camille E |title=Longitudinal Changes in the Relationship Between Hemoglobin A1c and Glucose Tolerance Across Pregnancy and Postpartum |journal=The Journal of Clinical Endocrinology & Metabolism |date=May 2020 |volume=105 |issue=5 |pages=e1999–e2007 |doi=10.1210/clinem/dgaa053 |pmid=32010954 |pmc=7236626 }}

Because women diagnosed with Gestational Diabetes (GDM) during pregnancy are at an increased risk for developing Type 2 Diabetes Mellitus after pregnancy, post-pregnancy glucose tolerance testing is needed.{{cite journal |last1=Noctor |first1=Eoin |title=Type 2 diabetes after gestational diabetes: The influence of changing diagnostic criteria |journal=World Journal of Diabetes |date=2015 |volume=6 |issue=2 |pages=234–244 |doi=10.4239/wjd.v6.i2.234 |doi-access=free |pmid=25789105 |pmc=4360417 }} Based on the recent meta-analysis conducted by the Patient-Centered Outcomes Research Institute, research has shown that post pregnancy testing reminders are associated with greater adherence to oral glucose tolerance testing up to 1 year postpartum.{{cite journal |last1=Saldanha |first1=Ian J. |last2=Adam |first2=Gaelen P. |last3=Kanaan |first3=Ghid |last4=Zahradnik |first4=Michael L. |last5=Steele |first5=Dale W. |last6=Danilack |first6=Valery A. |last7=Peahl |first7=Alex Friedman |last8=Chen |first8=Kenneth K. |last9=Stuebe |first9=Alison M. |last10=Balk |first10=Ethan M. |title=Postpartum Care up to 1 Year After Pregnancy: A Systematic Review and Meta-Analysis |date=2 June 2023 |doi=10.23970/AHRQEPCCER261 |pmid=37315166 }}

Opinions differ about optimal screening and diagnostic measures, in part due to differences in population risks, cost-effectiveness considerations, and lack of an evidence base to support large national screening programs.{{cite journal |last1=Berger |first1=Howard |last2=Crane |first2=Joan |last3=Farine |first3=Dan |title=Screening for Gestational Diabetes Mellitus |journal=Journal of Obstetrics and Gynaecology Canada |date=February 2003 |volume=25 |issue=2 |pages=96–6 |doi=10.1016/S1701-2163(16)30205-5 |pmid=12577126 }} The most elaborate regimen entails a random blood glucose test during a booking visit, a screening glucose challenge test around 24–28 weeks' gestation, followed by an OGTT if the tests are outside normal limits. If there is a high suspicion, a woman may be tested earlier.

In the United States, most obstetricians prefer universal screening with a screening glucose challenge test.{{Cite journal |vauthors=Gabbe SG, Gregory RP, Power ML, Williams SB, Schulkin J |date=June 2004 |title=Management of diabetes mellitus by obstetrician-gynecologists |journal=Obstetrics and Gynecology |volume=103 |issue=6 |pages=1229–34 |doi=10.1097/01.AOG.0000128045.50439.89 |pmid=15172857 }} In the United Kingdom, obstetric units often rely on risk factors and a random blood glucose test.{{Cite journal |vauthors=Mires GJ, Williams FL, Harper V |date=February 1999 |title=Screening practices for gestational diabetes mellitus in UK obstetric units |journal=Diabetic Medicine |volume=16 |issue=2 |pages=138–41 |doi=10.1046/j.1464-5491.1999.00011.x |pmid=10229307 }} The American Diabetes Association and the Society of Obstetricians and Gynaecologists of Canada recommend routine screening unless the woman is low risk (this means the woman must be younger than 25 years and have a body mass index less than 27, with no personal, ethnic or family risk factors) The Canadian Diabetes Association and the American College of Obstetricians and Gynecologists recommend universal screening.{{cite journal |last1=Thompson |first1=David |last2=Berger |first2=Howard |last3=Feig |first3=Denice |last4=Gagnon |first4=Robert |last5=Kader |first5=Tina |last6=Keely |first6=Erin |last7=Kozak |first7=Sharon |last8=Ryan |first8=Edmond |last9=Sermer |first9=Mathew |last10=Vinokuroff |first10=Christina |title=Diabetes and Pregnancy |journal=Canadian Journal of Diabetes |date=April 2013 |volume=37 |pages=S168–S183 |doi=10.1016/j.jcjd.2013.01.044 |pmid=24070943 }}{{Cite journal |vauthors=Gabbe SG, Graves CR |date=October 2003 |title=Management of diabetes mellitus complicating pregnancy |journal=Obstetrics and Gynecology |volume=102 |issue=4 |pages=857–68 |doi=10.1016/j.obstetgynecol.2003.07.001 |pmid=14551019}} The U.S. Preventive Services Task Force found there is insufficient evidence to recommend for or against routine screening,{{Cite journal |vauthors=Hillier TA, Vesco KK, Pedula KL, Beil TL, Whitlock EP, Pettitt DJ |date=May 2008 |title=Screening for gestational diabetes mellitus: a systematic review for the U.S. Preventive Services Task Force |journal=Annals of Internal Medicine |volume=148 |issue=10 |pages=766–75 |doi=10.7326/0003-4819-148-10-200805200-00009 |pmid=18490689 |doi-access=free}} and a 2017 a Cochrane review found that there is not evidence to determine which screening method is best for women and their babies.

Some pregnant women and care providers choose to forgo routine screening due to the absence of risk factors, however, this is not advised due to the large proportion of women who develop gestational diabetes despite having no risk factors present and the dangers to the mother and baby if gestational diabetes remains untreated.

When a plasma glucose level is found to be higher than 126 mg/dL (7.0 mmol/L) after fasting, or over 200 mg/dL (11.1 mmol/L) on any occasion, and if this is confirmed on a subsequent day, the diagnosis of GDM is made, and no further testing is required. These tests are typically performed at the first antenatal visit. They are simple to administer and inexpensive, but have a lower test performance compared to the other tests, with moderate sensitivity, low specificity and high false positive rates.{{Cite journal |vauthors=Agarwal MM, Dhatt GS |date=February 2007 |title=Fasting plasma glucose as a screening test for gestational diabetes mellitus |journal=Archives of Gynecology and Obstetrics |volume=275 |issue=2 |pages=81–7 |doi=10.1007/s00404-006-0245-9 |pmid=16967273 }}{{Cite journal |vauthors=Sacks DA, Chen W, Wolde-Tsadik G, Buchanan TA |date=June 2003 |title=Fasting plasma glucose test at the first prenatal visit as a screen for gestational diabetes |journal=Obstetrics and Gynecology |volume=101 |issue=6 |pages=1197–203 |doi=10.1016/s0029-7844(03)00049-8 |pmid=12798525 }}{{Cite journal |vauthors=Agarwal MM, Dhatt GS, Punnose J, Zayed R |date=April 2007 |title=Gestational diabetes: fasting and postprandial glucose as first prenatal screening tests in a high-risk population |journal=The Journal of Reproductive Medicine |volume=52 |issue=4 |pages=299–305 |pmid=17506370}}

The screening glucose challenge test (sometimes called the O'Sullivan test) is performed between 24 and 28 weeks, and can be seen as a simplified version of the oral glucose tolerance test (OGTT). No previous fasting is required for this screening test,[http://www.ddeamc.amedd.army.mil/clinical/pathology/DPALSGTT.aspx GLUCOSE TOLERANCE TEST] {{webarchive|url=https://archive.today/20121212203107/http://www.ddeamc.amedd.army.mil/clinical/pathology/DPALSGTT.aspx |date=2012-12-12 }} at the Dwight D. Eisenhower Army Medical Center. Last Modified November 25, 2009 in contrast to the OGTT. The O'Sullivan test involves drinking a solution containing 50 grams of glucose, and measuring blood levels one hour later.{{Cite web |year=2006 |title=What I need to know about Gestational Diabetes |url=http://diabetes.niddk.nih.gov/dm/pubs/gestational/ |url-status=live |archive-url=https://web.archive.org/web/20061126044339/http://diabetes.niddk.nih.gov/dm/pubs/gestational/ |archive-date=2006-11-26 |access-date=2006-11-27 |website=National Diabetes Information Clearinghouse |vauthors=Metzger BE, Biastre SA, Gardner B}}

If the cut-off point is set at 140 mg/dL (7.8 mmol/L), 80% of women with GDM will be detected. If this threshold for further testing is lowered to 130 mg/dL, 90% of GDM cases will be detected, but there will also be more women who will be subjected to a consequent OGTT unnecessarily.{{cn|date=January 2025}}

A standardized oral glucose tolerance test (OGTT){{MedlinePlusEncyclopedia|007562|Glucose screening tests during pregnancy}} should be done in the morning after an overnight fast of between 8 and 14 hours. During the three previous days, the subject must have an unrestricted diet (containing at least 150 g carbohydrate per day) and unlimited physical activity. The subject should remain seated during the test and should not smoke throughout the test.{{cn|date=January 2025}}

IADPSG (International Association of Diabetes and Pregnancy Study Groups) has developed diagnostic criteria for GDM, based on the results of adverse pregnancy outcomes in the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study.{{Cite journal |display-authors=6 |vauthors=Metzger BE, Lowe LP, Dyer AR, Trimble ER, Chaovarindr U, Coustan DR, Hadden DR, McCance DR, Hod M, McIntyre HD, Oats JJ, Persson B, Rogers MS, Sacks DA |date=May 2008 |title=Hyperglycemia and adverse pregnancy outcomes |journal=The New England Journal of Medicine |volume=358 |issue=19 |pages=1991–2002 |doi=10.1056/NEJMoa0707943 |pmid=18463375 |doi-access=free}} These were recommended by WHO 2013.{{cite book |title=Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy |date=2013 |publisher=World Health Organization |hdl=10665/85975 | vauthors = Organization WH }}{{pn|date=January 2025}}

According to these, gestational diabetes mellitus should be diagnosed at any time in pregnancy if one of the following criteria is met, using a 75 g glucose OGTT:{{cn|date=January 2025}}

• Fasting blood glucose level ≥92 mg/dL (5.1 mmol/L)
• 1 hour blood glucose level ≥180 mg/dL (10 mmol/L)
• 2 hour blood glucose level ≥153 mg/dL (8.5 mmol/L)

Women with GDM may have high glucose levels in their urine (glucosuria). Although dipstick testing is widely practiced, it performs poorly, and discontinuing routine dipstick testing has not been shown to cause underdiagnosis where universal screening is performed.{{Cite journal |vauthors=Rhode MA, Shapiro H, Jones OW |date=March 2007 |title=Indicated vs. routine prenatal urine chemical reagent strip testing |journal=The Journal of Reproductive Medicine |volume=52 |issue=3 |pages=214–9 |pmid=17465289}} Increased glomerular filtration rates during pregnancy contribute to some 50% of women having glucose in their urine on dipstick tests at some point during their pregnancy. Glomerular filtration rates increase during pregnancy due to an increase in blood volume to support the fetus.Hussein, Wael, and Richard A Lafayette. “Renal Function in Normal and Disordered Pregnancy.” Current Opinion in Nephrology and Hypertension, U.S. National Library of Medicine, Jan. 2014, pmc.ncbi.nlm.nih.gov/articles/PMC4117802/#:~:text=Recent%20findings,pressure%20and%20increased%20renal%20size. The sensitivity of glucosuria for GDM in the first two trimesters is only around 10%, and the positive predictive value is around 20%.{{Cite journal |vauthors=Alto WA |date=November 2005 |title=No need for glycosuria/proteinuria screen in pregnant women |journal=The Journal of Family Practice |volume=54 |issue=11 |pages=978–83 |id={{Gale|A138582366}} |pmid=16266604 |url=https://cdn.mdedge.com/files/s3fs-public/Document/September-2017/5411JFP_OriginalResearch.pdf }}{{Cite journal |vauthors=Ritterath C, Siegmund T, Rad NT, Stein U, Buhling KJ |year=2006 |title=Accuracy and influence of ascorbic acid on glucose-test with urine dip sticks in prenatal care |journal=Journal of Perinatal Medicine |volume=34 |issue=4 |pages=285–8 |doi=10.1515/JPM.2006.054 |pmid=16856816 }}

Vitamin D supplementation during pregnancy may help to prevent gestational diabetes.{{Cite journal |display-authors=6 |vauthors=Palacios C, Trak-Fellermeier MA, Martinez RX, Lopez-Perez L, Lips P, Salisi JA, John JC, Peña-Rosas JP |date=October 2019 |title=Regimens of vitamin D supplementation for women during pregnancy |journal=The Cochrane Database of Systematic Reviews |volume=2019 |issue=10 |pages=CD013446 |doi=10.1002/14651858.CD013446 |pmc=6776191 |pmid=31581312}} A 2015 review found that when done during pregnancy moderate physical exercise is effective for the prevention of gestational diabetes.{{Cite journal |vauthors=Sanabria-Martínez G, García-Hermoso A, Poyatos-León R, Álvarez-Bueno C, Sánchez-López M, Martínez-Vizcaíno V |date=August 2015 |title=Effectiveness of physical activity interventions on preventing gestational diabetes mellitus and excessive maternal weight gain: a meta-analysis |journal=BJOG |volume=122 |issue=9 |pages=1167–74 |doi=10.1111/1471-0528.13429 |pmid=26036300 }} A 2014 review however did not find a significant effect.{{Cite journal |vauthors=Yin YN, Li XL, Tao TJ, Luo BR, Liao SJ |date=February 2014 |title=Physical activity during pregnancy and the risk of gestational diabetes mellitus: a systematic review and meta-analysis of randomised controlled trials |journal=British Journal of Sports Medicine |volume=48 |issue=4 |pages=290–5 |doi=10.1136/bjsports-2013-092596 |pmid=24037671 }} It is uncertain if additional dietary advice interventions help to reduce the risk of gestational diabetes.{{Cite journal |vauthors=Tieu J, Shepherd E, Middleton P, Crowther CA |date=January 2017 |title=Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus |journal=The Cochrane Database of Systematic Reviews |volume=1 |issue=1 |pages=CD006674 |doi=10.1002/14651858.CD006674.pub3 |pmc=6464792 |pmid=28046205}} However, data from the Nurses' Health Study shows that adherence to a healthy plant-based diet is associated with lower risk for GDM.{{Cite journal |display-authors=6 |vauthors=Chen Z, Qian F, Liu G, Li M, Voortman T, Tobias DK, Ley SH, Bhupathiraju SN, Li LJ, Chavarro JE, Sun Q, Hu FB, Zhang C |date=December 2021 |title=Prepregnancy plant-based diets and the risk of gestational diabetes mellitus: a prospective cohort study of 14,926 women |journal=The American Journal of Clinical Nutrition |volume=114 |issue=6 |pages=1997–2005 |doi=10.1093/ajcn/nqab275 |pmc=8634573 |pmid=34510175}}

Diet and physical activity interventions designed to prevent excessive gestational weight gain reduce the rates of gestational diabetes. However, the impact of these interventions varies with the body mass index of the person as well as with the region in which the studies were performed.{{Cite journal |display-authors=6 |vauthors=Bennett CJ, Walker RE, Blumfield ML, Gwini SM, Ma J, Wang F, Wan Y, Dickinson H, Truby H |date=July 2018 |title=Interventions designed to reduce excessive gestational weight gain can reduce the incidence of gestational diabetes mellitus: A systematic review and meta-analysis of randomised controlled trials |journal=Diabetes Research and Clinical Practice |type=Review |volume=141 |pages=69–79 |doi=10.1016/j.diabres.2018.04.010 |pmid=29698713 }}

Moderate-quality evidence suggests that there is a reduced risk of gestational diabetes mellitus and caesarean section with combined diet and exercise interventions during pregnancy as well as reductions in gestational weight gain, compared with standard care.{{Cite journal |vauthors=Shepherd E, Gomersall JC, Tieu J, Han S, Crowther CA, Middleton P |date=November 2017 |title=Combined diet and exercise interventions for preventing gestational diabetes mellitus |journal=The Cochrane Database of Systematic Reviews |volume=2017 |issue=11 |pages=CD010443 |doi=10.1002/14651858.cd010443.pub3 |pmc=6485974 |pmid=29129039}}

A 2023 review found that a plant-based diet (including fruits, vegetables, whole grains, nuts and seeds, and tea) rich in phytochemicals lowers the risk of GDM.{{Cite journal |vauthors=Jaworsky K, DeVillez P, Basu A |date=February 2023 |title=The Role of Phytochemicals and Plant-Based Diets in Gestational Diabetes: Evidence from Clinical Trials |journal=International Journal of Environmental Research and Public Health |volume=20 |issue=5 |pages=4188 |doi=10.3390/ijerph20054188 |pmc=10001985 |pmid=36901197 |doi-access=free}} A Cochrane review, updated 2023, stated that myo‐inositol has a potential beneficial effect of improving insulin sensitivity, which suggested that it may be useful for women in preventing gestational diabetes″.{{Cite journal |last=Soana K Motuhifonuaa, Luling Lina. Jane Alsweiler, Tineke J Crawford, Caroline A Crowther |date=15 February 2023 |title=Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes |journal= Cochrane Database of Systematic Reviews|volume=2023 |issue=2 |pages=CD011507 |doi=10.1002/14651858.CD011507.pub3 |pmc=9930614 |pmid=36790138}}

It has been suggested that for women who have had gestational diabetes, diet, exercise, education, and lifestyle changes between pregnancies may lower their chances of having gestational diabetes again in future pregnancies.{{Cite journal |vauthors=Tieu J, Shepherd E, Middleton P, Crowther CA |date=August 2017 |title=Interconception care for women with a history of gestational diabetes for improving maternal and infant outcomes |journal=The Cochrane Database of Systematic Reviews |volume=2017 |issue=8 |pages=CD010211 |doi=10.1002/14651858.CD010211.pub3 |pmc=6483533 |pmid=28836274}} For women with a normal BMI pre-pregnancy, light to moderate exercise for 30-60 minutes three times a week during pregnancy can decrease the occurrence of GDM.{{cite journal |last1=Ming |first1=Wai-Kit |last2=Ding |first2=Wenjing |last3=Zhang |first3=Casper J. P. |last4=Zhong |first4=Lieqiang |last5=Long |first5=Yuhang |last6=Li |first6=Zhuyu |last7=Sun |first7=Cong |last8=Wu |first8=Yanxin |last9=Chen |first9=Hanqing |last10=Chen |first10=Haitian |last11=Wang |first11=Zilian |title=The effect of exercise during pregnancy on gestational diabetes mellitus in normal-weight women: a systematic review and meta-analysis |journal=BMC Pregnancy and Childbirth |date=December 2018 |volume=18 |issue=1 |page=440 |doi=10.1186/s12884-018-2068-7 |doi-access=free |pmc=6233372 |pmid=30419848 }} It was found that women who completed at least 600 MET-min/week of moderate intensity exercise can cause at least a 25% reduction in the odds of developing GDM.{{cite journal |last1=Davenport |first1=Margie H |last2=Ruchat |first2=Stephanie-May |last3=Poitras |first3=Veronica J |last4=Jaramillo Garcia |first4=Alejandra |last5=Gray |first5=Casey E |last6=Barrowman |first6=Nick |last7=Skow |first7=Rachel J |last8=Meah |first8=Victoria L |last9=Riske |first9=Laurel |last10=Sobierajski |first10=Frances |last11=James |first11=Marina |last12=Kathol |first12=Amariah J |last13=Nuspl |first13=Megan |last14=Marchand |first14=Andree-Anne |last15=Nagpal |first15=Taniya S |last16=Slater |first16=Linda G |last17=Weeks |first17=Ashley |last18=Adamo |first18=Kristi B |last19=Davies |first19=Gregory A |last20=Barakat |first20=Ruben |last21=Mottola |first21=Michelle F |title=Prenatal exercise for the prevention of gestational diabetes mellitus and hypertensive disorders of pregnancy: a systematic review and meta-analysis |journal=British Journal of Sports Medicine |date=November 2018 |volume=52 |issue=21 |pages=1367–1375 |id={{ProQuest|2122258735}} |doi=10.1136/bjsports-2018-099355 |pmid=30337463 }} When studying the difference effects between aerobic and resistance training, it was found that there were no differences in fasting blood glucose levels, insulin utilization rate, or pregnancy outcomes. However, there was an better improvement in the 2-hour postprandial blood glucose level. The resistance training group was also more compliant with their workout program than the aerobic group.{{cite journal |last1=Xie |first1=Yaping |last2=Zhao |first2=Huifen |last3=Zhao |first3=Meijing |last4=Huang |first4=Huibin |last5=Liu |first5=Chunhong |last6=Huang |first6=Fengfeng |last7=Wu |first7=Jingjing |title=Effects of resistance exercise on blood glucose level and pregnancy outcome in patients with gestational diabetes mellitus: a randomized controlled trial |journal=BMJ Open Diabetes Research & Care |date=April 2022 |volume=10 |issue=2 |pages=e002622 |doi=10.1136/bmjdrc-2021-002622 |pmid=35383101 |pmc=8984031 }} Based on this information, resistance training may be a better option for women with gestational diabetes, but doing both aerobic training and resistance training would be optimal.{{cn|date=January 2025}}

{{main|Diabetes management}}

File:Gestational diabetes kit.jpg

Treatment of GDM with diet and insulin reduces health problems for the mother and child.{{Cite journal |vauthors=Alwan N, Tuffnell DJ, West J |date=July 2009 |title=Treatments for gestational diabetes |journal=The Cochrane Database of Systematic Reviews |volume=2009 |issue=3 |pages=CD003395 |doi=10.1002/14651858.CD003395.pub2 |pmc=7154381 |pmid=19588341}} Treatment of GDM is also accompanied by more inductions of labour.

A repeat OGTT should be carried out 6 weeks after delivery, to confirm that diabetes has disappeared. Afterwards, regular screening for type 2 diabetes is advised.

Lifestyle interventions include exercise, diet advice, behavioural interventions, relaxation, self-monitoring of glucose, and combined interventions.{{Cite journal |vauthors=Brown J, Alwan NA, West J, Brown S, McKinlay CJ, Farrar D, Crowther CA |date=May 2017 |title=Lifestyle interventions for the treatment of women with gestational diabetes |journal=The Cochrane Database of Systematic Reviews |volume=2017 |issue=5 |pages=CD011970 |doi=10.1002/14651858.CD011970.pub2 |pmc=6481373 |pmid=28472859 |hdl=10292/10707 }} Women with gestational diabetes who receive lifestyle interventions seem to have less postpartum depression, and were more likely to reach their weight loss targets after giving birth, than women who had no intervention. Their babies are also less likely to be large for their gestational age, and have less percentage of fat when they are born. More research is needed to discover the most effective lifestyle interventions. Some women with GDM use probiotics, but it is very uncertain if there are any benefits in terms of blood glucose levels, high blood pressure disorders, or induction of labour.{{Cite journal |vauthors=Okesene-Gafa KA, Moore AE, Jordan V, McCowan L, Crowther CA |date=June 2020 |title=Probiotic treatment for women with gestational diabetes to improve maternal and infant health and well-being |journal=The Cochrane Database of Systematic Reviews |volume=2020 |issue=6 |pages=CD012970 |doi=10.1002/14651858.CD012970.pub2 |pmc=7386668 |pmid=32575163}}

If a diabetic diet or G.I. Diet, exercise, and oral medication are inadequate to control glucose levels, insulin therapy may become necessary.{{cn|date=April 2023}}

The development of macrosomia can be evaluated during pregnancy by using sonography. Women who use insulin, with a history of stillbirth, or with hypertension are managed like women with overt diabetes.

Researchers have found ways for pregnant women with gestational diabetes to reduce their complications with their current health, long-term effects, and fetal health with the help of exercise. Laredo-Aguilera, et al., and Dipla, et al., presented findings from systematic and meta-analyses that showed positive effects of resistance exercise or a combination of resistance and aerobic exercise. Aerobic and resistance training were found to control glucose, HgbA1c, and insulin levels in women with GDM. Not only is the mother's health affected, but also the fetus's. If GDM is not treated or is made worse, the child may suffer from macrosomia, impaired intrauterine growth, obstetric trauma, hyperbilirubinemia, hypoglycemia, or even infection. Pregnant women with GDM who are overweight or obese are at a greater risk of passing down these negative effects by 2.14-3.56 times. Benefits to resistance and aerobic exercise include a maternal decrease in cramps, lower back pain, edema, depression, urinary incontinence, duration of labor, constipation, and the number of c-sections. These benefits can affect the fetus by having a decreased body fat mass, improved stress tolerance, and advanced neurobehavioral maturation. In the article written by Laredo-Aguilera, et al.,{{cite journal |last1=Laredo-Aguilera |first1=José Alberto |last2=Gallardo-Bravo |first2=María |last3=Rabanales-Sotos |first3=Joseba Aingerun |last4=Cobo-Cuenca |first4=Ana Isabel |last5=Carmona-Torres |first5=Juan Manuel |title=Physical Activity Programs during Pregnancy Are Effective for the Control of Gestational Diabetes Mellitus |journal=International Journal of Environmental Research and Public Health |date=24 August 2020 |volume=17 |issue=17 |pages=6151 |doi=10.3390/ijerph17176151 |doi-access=free |pmid=32847106 |pmc=7503359 }} there were seven interventions and seven different countries that were used for research. Within all of the interventions, there were significant improvements in glucose concentration, reduced requirements of insulin injections, postprandial glucose level control, and glycemic control. The study reviewed by Dipla, et al.,{{cite journal |last1=Dipla |first1=Konstantina |last2=Zafeiridis |first2=Andreas |last3=Mintziori |first3=Gesthimani |last4=Boutou |first4=Afroditi K. |last5=Goulis |first5=Dimitrios G. |last6=Hackney |first6=Anthony C. |title=Exercise as a Therapeutic Intervention in Gestational Diabetes Mellitus |journal=Endocrines |date=26 March 2021 |volume=2 |issue=2 |pages=65–78 |doi=10.3390/endocrines2020007 |doi-access=free |pmid=33870263 |pmc=8046020 }} found that even a single exercise bout increases skeletal muscle glucose uptake, minimizing hyperglycemia. Regular exercise training has been found to promote mitochondrial biogenesis, improve oxidative capacity, enhance insulin sensitivity and vascular function, and reduce systemic inflammation in women with GDM. Women with GDM must provide enough glucose to the fetus, but often become insulin resistant. Exercise has been previously known to be dangerous for women during pregnancy, but now multiple studies have found otherwise. It is very important for women with gestational diabetes to measure their heart rate reserve to determine exercise intensity and exercise at an RPE between 12 and 14. {{cn|date=January 2025}} 

Counselling before pregnancy (for example, about preventive folic acid supplements) and multidisciplinary management are important for good pregnancy outcomes.{{Cite journal |vauthors=Kapoor N, Sankaran S, Hyer S, Shehata H |date=December 2007 |title=Diabetes in pregnancy: a review of current evidence |journal=Current Opinion in Obstetrics & Gynecology |volume=19 |issue=6 |pages=586–90 |doi=10.1097/GCO.0b013e3282f20aad |pmid=18007138 }} Most women can manage their GDM with dietary changes and exercise. Self-monitoring of blood glucose levels can guide therapy. Some women will need antidiabetic drugs, most commonly insulin therapy.{{cn|date=April 2023}}

Any diet needs to provide sufficient calories for pregnancy, typically 2,000–2,500 kcal with the exclusion of simple carbohydrates. The main goal of dietary modifications is to avoid peaks in blood sugar levels. This can be done by spreading carbohydrate intake over meals and snacks throughout the day, and using slow-release carbohydrate sources—known as the G.I. Diet. Since insulin resistance is highest in the morning, breakfast carbohydrates must be restricted more.

The Mediterranean diet may be associated with reduced incidence of gestational diabetes.{{Cite journal |vauthors=Zhang Y, Xia M, Weng S, Wang C, Yuan P, Tang S |date=December 2022 |title=Effect of Mediterranean diet for pregnant women: a meta-analysis of randomized controlled trials |journal=The Journal of Maternal-Fetal & Neonatal Medicine |volume=35 |issue=24 |pages=4824–4829 |doi=10.1080/14767058.2020.1868429 |pmid=33632052 }} However, there is not enough evidence to indicate if one type of dietary advice is better than another.{{cite journal |last1=Han |first1=Shanshan |last2=Middleton |first2=Philippa |last3=Shepherd |first3=Emily |last4=Van Ryswyk |first4=Emer |last5=Crowther |first5=Caroline A |title=Different types of dietary advice for women with gestational diabetes mellitus |journal=Cochrane Database of Systematic Reviews |date=25 February 2017 |volume=2017 |issue=4 |pages=CD009275 |doi=10.1002/14651858.CD009275.pub3 |pmid=28236296 |pmc=6464700 }}

Though there is no specific structure for exercise programs for GDM, it is understood that being subjected to constant exposure to a sedentary lifestyle and participating in <2999 MET-mins a week in physical activity is linked to a 10 times higher risk of developing GDM.{{Cite journal |last1=Mishra |first1=Surabhi |last2=Kishore |first2=Surekha |date=October 2018 |title=Effect of Physical Activity during Pregnancy on Gestational Diabetes Mellitus |journal=Indian Journal of Endocrinology and Metabolism |language=en-US |volume=22 |issue=5 |pages=661–671 |doi=10.4103/ijem.IJEM_618_17 |doi-access=free |pmid=30294578 |pmc=6166569 }} Conversely, partaking in  > 3000 MET-mins of any physical activity can reduce developing GDM. However, light intensity walking is an effective way to help control casual glucose level (CGL), but a minimum of 6000 steps must be achieved daily to have consistent effectiveness in controlling CGL.{{Cite journal |last1=Hayashi |first1=Ayako |last2=Oguchi |first2=Hidenori |last3=Kozawa |first3=Yumi |last4=Ban |first4=Yukiko |last5=Shinoda |first5=Junji |last6=Suganuma |first6=Nobuhiko |date=September 2018 |title=Daily walking is effective for the management of pregnant women with gestational diabetes mellitus |journal=Journal of Obstetrics and Gynaecology Research |volume=44 |issue=9 |pages=1731–1738 |doi=10.1111/jog.13698 |pmc=6174974 |pmid=29974564 }} Nevertheless there is no significant correlation between light intensity walking and hbA1c, therefore regular moderate intensity exercise is advised, specifically aerobic exercise has been proven to improve both fasting and postprandial blood glucose, insulin dosage, and insulin usage within the body.{{Cite journal |last1=Yaping |first1=Xie |last2=Huifen |first2=Zhao |last3=Meijing |first3=Zhao |last4=Huibin |first4=Huang |last5=Chunhong |first5=Liu |last6=Fengfeng |first6=Huang |last7=Jingjing |first7=Wu |date=September 2021 |title=Effects of Moderate-Intensity Aerobic Exercise on Blood Glucose Levels and Pregnancy Outcomes in Patients With Gestational Diabetes Mellitus: A Randomized Controlled Trial |url=https://link.springer.com/article/10.1007/s13300-021-01135-6 |journal=Diabetes Therapy |language=en |volume=12 |issue=9 |pages=2585–2598 |doi=10.1007/s13300-021-01135-6 |doi-broken-date=2024-11-13 |pmc=8384942 |pmid=34387823}}  It is still contested which form of exercise/physical activity is best for pregnant women, yet some movement is better than no movement.{{cn|date=January 2025}}

Although exercise does not reduce the risk of developing GDM, it does help reduce some of the associated risks.{{cite journal |last1=Barakat |first1=Ruben |last2=Pelaez |first2=Mireia |last3=Lopez |first3=Carmina |last4=Lucia |first4=Alejandro |last5=Ruiz |first5=Jonatan R |title=Exercise during pregnancy and gestational diabetes-related adverse effects: a randomised controlled trial |journal=British Journal of Sports Medicine |date=July 2013 |volume=47 |issue=10 |pages=630–636 |doi=10.1136/bjsports-2012-091788 |pmid=23365418 |url=http://oa.upm.es/29189/ }} When it comes to exercise in pregnant women who have GDM there is a decrease in the risk of having a newborn with macrosomia, decrease in maternal weight gain and a decrease in c-sections. Although exercise is not the cure for GDM, it does help pregnant women decrease any complications or risk factors that can arise from the disease.{{cn|date=January 2025}}

Self-monitoring can be accomplished using a handheld capillary glucose dosage system. Compliance with these glucometer systems can be low. There is not a lot of research into what target blood sugar levels should be for women with gestational diabetes, and targets recommended to women vary globally.{{Cite journal |vauthors=Hofer OJ, Martis R, Alsweiler J, Crowther CA |date=October 2023 |title=Different intensities of glycaemic control for women with gestational diabetes mellitus |journal=The Cochrane Database of Systematic Reviews |volume=2023 |issue=10 |pages=CD011624 |doi=10.1002/14651858.CD011624.pub3 |pmc=10563388 |pmid=37815094 }} Target ranges advised by the Australasian Diabetes in Pregnancy Society are as follows:

• fasting capillary blood glucose levels <5.5 mmol/L
• 1 hour postprandial capillary blood glucose levels <8.0 mmol/L
• 2 hour postprandial blood glucose levels <6.7 mmol/L

Regular blood samples can be used to determine HbA1c levels, which give an idea of glucose control over a longer period.

Research suggests a possible benefit of breastfeeding to reduce the risk of diabetes and related risks for both mother and child.{{Cite journal |vauthors=Taylor JS, Kacmar JE, Nothnagle M, Lawrence RA |date=October 2005 |title=A systematic review of the literature associating breastfeeding with type 2 diabetes and gestational diabetes |journal=Journal of the American College of Nutrition |volume=24 |issue=5 |pages=320–6 |doi=10.1080/07315724.2005.10719480 |pmid=16192255 }}

If monitoring reveals failing control of glucose levels with these measures, or if there is evidence of complications like excessive fetal growth, treatment with insulin might be necessary. This is most commonly fast-acting insulin given just before eating to blunt glucose rises after meals. Care needs to be taken to avoid low blood sugar levels due to excessive insulin. Insulin therapy can be normal or very tight; more injections can result in better control but require more effort, and there is no consensus that it has large benefits.{{Cite journal |vauthors=Nachum Z, Ben-Shlomo I, Weiner E, Shalev E |date=November 1999 |title=Twice daily versus four times daily insulin dose regimens for diabetes in pregnancy: randomised controlled trial |journal=BMJ |volume=319 |issue=7219 |pages=1223–7 |doi=10.1136/bmj.319.7219.1223 |pmc=28269 |pmid=10550081}} A 2016 Cochrane review (updated in 2023) concluded that quality evidence is not yet available to determine the best blood sugar range for improving health for pregnant women with GDM and their babies.

There is some evidence that certain medications by mouth might be safe in pregnancy, or at least, are less dangerous to the developing fetus than poorly controlled diabetes. When comparing which diabetes tablets (medication by mouth) work best and are safest, there is not enough quality research to support one medication over another.{{Cite journal |vauthors=Brown J, Martis R, Hughes B, Rowan J, Crowther CA |date=January 2017 |title=Oral anti-diabetic pharmacological therapies for the treatment of women with gestational diabetes |department=review |journal=The Cochrane Database of Systematic Reviews |volume=1 |issue=1 |pages=CD011967 |doi=10.1002/14651858.CD011967.pub2 |pmc=6464763 |pmid=28120427}} The medication metformin is better than glyburide.{{Cite journal |vauthors=Balsells M, García-Patterson A, Solà I, Roqué M, Gich I, Corcoy R |date=January 2015 |title=Glibenclamide, metformin, and insulin for the treatment of gestational diabetes: a systematic review and meta-analysis |journal=BMJ |volume=350 |pages=h102 |doi=10.1136/bmj.h102 |pmc=4301599 |pmid=25609400 |doi-access=free}} If blood glucose cannot be adequately controlled with a single agent, the combination of metformin and insulin may be better than insulin alone. Another review found good short term safety for both the mother and baby with metformin but unclear long term safety.{{Cite journal |vauthors=Butalia S, Gutierrez L, Lodha A, Aitken E, Zakariasen A, Donovan L |date=January 2017 |title=Short- and long-term outcomes of metformin compared with insulin alone in pregnancy: a systematic review and meta-analysis |journal=Diabetic Medicine |volume=34 |issue=1 |pages=27–36 |doi=10.1111/dme.13150 |pmid=27150509 }}

People may prefer metformin by mouth to insulin injections. Treatment of polycystic ovarian syndrome with metformin during pregnancy has been noted to decrease GDM levels.{{Cite journal |vauthors=Simmons D, Walters BN, Rowan JA, McIntyre HD |date=May 2004 |title=Metformin therapy and diabetes in pregnancy |journal=The Medical Journal of Australia |volume=180 |issue=9 |pages=462–4 |doi=10.5694/j.1326-5377.2004.tb06024.x |pmid=15115425 }}

Almost half of the women did not reach sufficient control with metformin alone and needed supplemental therapy with insulin; compared to those treated with insulin alone, they required less insulin, and they gained less weight. With no long-term studies into children of women treated with the drug, there remains a possibility of long-term complications from metformin therapy. Babies born to women treated with metformin have been found to develop less visceral fat, making them less prone to insulin resistance in later life.{{Cite journal |vauthors=Sivalingam VN, Myers J, Nicholas S, Balen AH, Crosbie EJ |year=2014 |title=Metformin in reproductive health, pregnancy and gynaecological cancer: established and emerging indications |journal=Human Reproduction Update |volume=20 |issue=6 |pages=853–68 |doi=10.1093/humupd/dmu037 |pmid=25013215 |doi-access=free}}

Gestational diabetes generally resolves once the baby is born. Based on different studies, the chances of developing GDM in a second pregnancy, if a woman had GDM in her first pregnancy, are between 30 and 84%, depending on ethnic background. A second pregnancy within one year of the previous pregnancy has a large likelihood of GDM recurrence.{{Cite journal |vauthors=Kim C, Berger DK, Chamany S |date=May 2007 |title=Recurrence of gestational diabetes mellitus: a systematic review |journal=Diabetes Care |volume=30 |issue=5 |pages=1314–9 |doi=10.2337/dc06-2517 |pmid=17290037 |doi-access=free}}

Women diagnosed with gestational diabetes have an increased risk of developing diabetes mellitus in the future. The risk is highest in women who needed insulin treatment, had antibodies associated with diabetes (such as antibodies against glutamate decarboxylase, islet cell antibodies, or insulinoma antigen-2), women with more than two previous pregnancies, and women who were obese (in order of importance).{{Cite journal |vauthors=Löbner K, Knopff A, Baumgarten A, Mollenhauer U, Marienfeld S, Garrido-Franco M, Bonifacio E, Ziegler AG |date=March 2006 |title=Predictors of postpartum diabetes in women with gestational diabetes mellitus |journal=Diabetes |volume=55 |issue=3 |pages=792–7 |doi=10.2337/diabetes.55.03.06.db05-0746 |pmid=16505245 |doi-access=free}}{{Cite journal |vauthors=Järvelä IY, Juutinen J, Koskela P, Hartikainen AL, Kulmala P, Knip M, Tapanainen JS |date=March 2006 |title=Gestational diabetes identifies women at risk for permanent type 1 and type 2 diabetes in fertile age: predictive role of autoantibodies |journal=Diabetes Care |volume=29 |issue=3 |pages=607–12 |doi=10.2337/diacare.29.03.06.dc05-1118 |pmid=16505514 |doi-access=free}} Women requiring insulin to manage gestational diabetes have a 50% risk of developing diabetes within the next five years.{{Cite web |year=2006 |title=Gestational Diabetes |url=http://www.health.am/pregnancy/gestational-diabetes/ |url-status=live |archive-url=https://web.archive.org/web/20070105021030/http://www.health.am/pregnancy/gestational-diabetes/ |archive-date=2007-01-05 |access-date=2006-11-27 |website=Diabetes Mellitus & Pregnancy – Gestational Diabetes |publisher=Armenian Medical Network |vauthors=Janzen C, Greenspoon JS}} Depending on the population studied, the diagnostic criteria and the length of follow-up, the risk can vary enormously.{{Cite journal |vauthors=Kim C, Newton KM, Knopp RH |date=October 2002 |title=Gestational diabetes and the incidence of type 2 diabetes: a systematic review |journal=Diabetes Care |volume=25 |issue=10 |pages=1862–8 |doi=10.2337/diacare.25.10.1862 |pmid=12351492 |doi-access=free}} The risk appears to be highest in the first 5 years, reaching a plateau thereafter. One of the longest studies followed a group of women from Boston, Massachusetts; half of them developed diabetes after 6 years, and more than 70% had diabetes after 28 years. In a retrospective study in Navajo women, the risk of diabetes after GDM was estimated to be 50 to 70% after 11 years.{{Cite journal |vauthors=Steinhart JR, Sugarman JR, Connell FA |date=June 1997 |title=Gestational diabetes is a herald of NIDDM in Navajo women. High rate of abnormal glucose tolerance after GDM |journal=Diabetes Care |volume=20 |issue=6 |pages=943–7 |doi=10.2337/diacare.20.6.943 |pmid=9167104 }} Another study found a risk of diabetes after GDM of more than 25% after 15 years.{{Cite journal |vauthors=Lee AJ, Hiscock RJ, Wein P, Walker SP, Permezel M |date=April 2007 |title=Gestational diabetes mellitus: clinical predictors and long-term risk of developing type 2 diabetes: a retrospective cohort study using survival analysis |journal=Diabetes Care |volume=30 |issue=4 |pages=878–83 |doi=10.2337/dc06-1816 |pmid=17392549 |doi-access=free}} In populations with a low risk for type 2 diabetes, in lean subjects and in women with auto-antibodies, there is a higher rate of women developing type 1 diabetes (LADA).

Children of women with GDM have an increased risk for childhood and adult obesity and an increased risk of glucose intolerance and type 2 diabetes later in life.{{Cite journal |vauthors=Boney CM, Verma A, Tucker R, Vohr BR |date=March 2005 |title=Metabolic syndrome in childhood: association with birth weight, maternal obesity, and gestational diabetes mellitus |journal=Pediatrics |volume=115 |issue=3 |pages=e290-6 |doi=10.1542/peds.2004-1808 |pmid=15741354 |doi-access=free}} This risk relates to increased maternal glucose values.{{Cite journal |vauthors=Hillier TA, Pedula KL, Schmidt MM, Mullen JA, Charles MA, Pettitt DJ |date=September 2007 |title=Childhood obesity and metabolic imprinting: the ongoing effects of maternal hyperglycemia |journal=Diabetes Care |volume=30 |issue=9 |pages=2287–92 |doi=10.2337/dc06-2361 |pmid=17519427 |doi-access=free}} It is currently unclear how much genetic susceptibility and environmental factors contribute to this risk, and whether treatment of GDM can influence this outcome.{{Cite journal |vauthors=Metzger BE |date=December 2007 |title=Long-term outcomes in mothers diagnosed with gestational diabetes mellitus and their offspring |journal=Clinical Obstetrics and Gynecology |volume=50 |issue=4 |pages=972–9 |doi=10.1097/GRF.0b013e31815a61d6 |pmid=17982340}}

The relative benefits and harms of different oral anti-diabetic medications are not yet well understood as of 2017.

There are scarce statistical data on the risk of other conditions in women with GDM; in the Jerusalem Perinatal study, 410 out of 37,962 women were reported to have GDM, and there was a tendency towards more breast and pancreatic cancer, but more research is needed to confirm this finding.{{Cite journal |vauthors=Perrin MC, Terry MB, Kleinhaus K, Deutsch L, Yanetz R, Tiram E, Calderon-Margalit R, Friedlander Y, Paltiel O, Harlap S |date=March 2008 |title=Gestational diabetes and the risk of breast cancer among women in the Jerusalem Perinatal Study |journal=Breast Cancer Research and Treatment |volume=108 |issue=1 |pages=129–35 |doi=10.1007/s10549-007-9585-9 |pmid=17476589 }}{{Cite journal |vauthors=Perrin MC, Terry MB, Kleinhaus K, Deutsch L, Yanetz R, Tiram E, Calderon R, Friedlander Y, Paltiel O, Harlap S |date=August 2007 |title=Gestational diabetes as a risk factor for pancreatic cancer: a prospective cohort study |journal=BMC Medicine |volume=5 |issue=1 |pages=25 |doi=10.1186/1741-7015-5-25 |pmc=2042496 |pmid=17705823 |doi-access=free}}

Research is being conducted to develop a web-based clinical decision support system for GDM prediction using machine learning techniques. Results so far demonstrated great potential in clinical practicality for automatic GDM prognosis.{{Cite journal |vauthors=Du Y, Rafferty AR, McAuliffe FM, Wei L, Mooney C |date=January 2022 |title=An explainable machine learning-based clinical decision support system for prediction of gestational diabetes mellitus |journal=Scientific Reports |volume=12 |issue=1 |pages=1170 |bibcode=2022NatSR..12.1170D |doi=10.1038/s41598-022-05112-2 |pmc=8782851 |pmid=35064173}}

GDM poses a risk to mother and child. This risk is largely related to uncontrolled blood glucose levels and their consequences. The risk increases with higher blood glucose levels.{{Cite journal |first12=J. J. |first13=B. |first14=M. S. |first15=D. A. |vauthors=Metzger BE, Lowe LP, Dyer AR, Trimble ER, Chaovarindr U, Coustan DR, Hadden DR, McCance DR, Hod M, McIntyre HD, Oats JJ, Persson B, Rogers MS, Sacks DA |date=May 2008 |title=Hyperglycemia and adverse pregnancy outcomes |url=http://espace.library.uq.edu.au/view/UQ:165894/UQ165894_OA.pdf |journal=The New England Journal of Medicine |volume=358 |issue=19 |pages=1991–2002 |doi=10.1056/NEJMoa0707943 |pmid=18463375}} Treatment resulting in better control of these levels can reduce some of the risks of GDM considerably.{{Cite journal |vauthors=Langer O, Rodriguez DA, Xenakis EM, McFarland MB, Berkus MD, Arrendondo F |date=April 1994 |title=Intensified versus conventional management of gestational diabetes |journal=American Journal of Obstetrics and Gynecology |volume=170 |issue=4 |pages=1036–46; discussion 1046–7 |doi=10.1016/S0002-9378(94)70097-4 |pmid=8166187}}

Having GDM can lead to mental health issues with the distress added to the pregnancy. Women with gestational diabetes experienced increased anxiety, depression, and stress.{{Cite journal |last1=Grinberg |first1=Keren |last2=Yisaschar-Mekuzas |first2=Yael |date=January 2024 |title=Assessing Mental Health Conditions in Women with Gestational Diabetes Compared to Healthy Pregnant Women |journal=Healthcare |volume=12 |issue=14 |pages=1438 |doi=10.3390/healthcare12141438 |doi-access=free |pmid=39057581 |pmc=11276048 }} Not only does it affect mental health during pregnancy, but it also leads to an increased risk of postpartum depression.{{cite journal |last1=Nicolazzi |first1=Ludmila |last2=Gilbert |first2=Leah |last3=Horsch |first3=Antje |last4=Quansah |first4=Dan Yedu |last5=Puder |first5=Jardena J. |title=Trajectories and associations of symptoms of mental health and well-being with insulin resistance and metabolic health in women with gestational diabetes |journal=Psychoneuroendocrinology |date=February 2024 |volume=160 |pages=106919 |doi=10.1016/j.psyneuen.2023.106919 |pmid=38091918 }} The risk is over 4 times greater than a normal pregnancy. It was found that physical activity could decrease the risk for postpartum depression. It is a form of therapy that can help reduce the stress of these mental health issues.{{Cite journal |last1=Rieß |first1=Claudia |last2=Heimann |first2=Yvonne |last3=Schleußner |first3=Ekkehard |last4=Groten |first4=Tanja |last5=Weschenfelder |first5=Friederike |date=January 2023 |title=Disease Perception and Mental Health in Pregnancies with Gestational Diabetes—PsychDiab Pilot Study |journal=Journal of Clinical Medicine |volume=12 |issue=10 |pages=3358 |doi=10.3390/jcm12103358 |doi-access=free |pmid=37240463 |pmc=10219351 }}

The two main risks GDM imposes on the baby are growth abnormalities and chemical imbalances after birth, which may require admission to a neonatal intensive care unit. Infants born to mothers with GDM are at risk of being both large for gestational age (macrosomic) in unmanaged GDM, and small for gestational age and Intrauterine growth retardation{{Cite journal |vauthors=Setji TL, Brown AJ, Feinglos MN |date=1 January 2005 |title=Gestational Diabetes Mellitus |journal=Clinical Diabetes |volume=23 |issue=1 |pages=17–24 |doi=10.2337/diaclin.23.1.17 |doi-access=free}} in managed GDM. Macrosomia in turn increases the risk of instrumental deliveries (e.g. forceps, ventouse and caesarean section) or problems during vaginal delivery (such as shoulder dystocia). Macrosomia may affect 12% of normal women compared to 20% of women with GDM. However, the evidence for each of these complications is not equally strong; in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study for example, there was an increased risk for babies to be large but not small for gestational age in women with uncontrolled GDM. In a recent birth cohort study of 5150 deliveries, a research group active at the University of Helsinki and Helsinki University Hospital, Finland demonstrated that the mother's GDM is an independent factor that increases the risk of fetal hypoxia, during labour. The study was published in the Acta Diabetologica in June 2021.{{Cite journal |vauthors=Tarvonen M, Hovi P, Sainio S, Vuorela P, Andersson S, Teramo K |date=2021 |title=Intrapartal cardiotocographic patterns and hypoxia-related perinatal outcomes in pregnancies complicated by gestational diabetes mellitus |journal=Acta Diabetologica |volume=58 |issue=11 |pages=1563–1573 |doi=10.1007/s00592-021-01756-0 |pmc=8505288 |pmid=34151398}} Another finding was that GDM increased the susceptibility of the fetus to intrapartum hypoxia, regardless of the size of the fetus. The risk of hypoxia and the resulting risk of poor condition in newborn infants was nearly 7-fold in the fetuses of mothers with GDM compared to the fetuses of non-diabetic mothers. Furthermore, according to the findings, the risk of needing to perform resuscitation on the newborn after birth was 10-fold.

Another finding was that gestational diabetes increased the susceptibility of the fetus to intrapartum hypoxia, regardless of the size of the fetus.{{cn|date=April 2023}}

"The risk of hypoxia and the resulting risk of poor condition in newborn infants was nearly seven-fold in the fetuses of mothers with gestational diabetes compared to the fetuses of non-diabetic mothers," says researcher Mikko Tarvonen. According to the findings, the risk of needing to perform resuscitation on the newborn was tenfold. Research into complications for GDM is difficult because of the many confounding factors (such as obesity). Labelling a woman as having GDM may in itself increase the risk of having an unnecessary caesarean section.{{Cite journal |vauthors=Naylor CD, Sermer M, Chen E, Farine D |date=November 1997 |title=Selective screening for gestational diabetes mellitus. Toronto Trihospital Gestational Diabetes Project Investigators |journal=The New England Journal of Medicine |volume=337 |issue=22 |pages=1591–6 |doi=10.1056/NEJM199711273372204 |pmid=9371855 |doi-access=free}}{{Cite journal |vauthors=Jovanovic-Peterson L, Bevier W, Peterson CM |date=April 1997 |title=The Santa Barbara County Health Care Services program: birth weight change concomitant with screening for and treatment of glucose-intolerance of pregnancy: a potential cost-effective intervention? |journal=American Journal of Perinatology |volume=14 |issue=4 |pages=221–8 |doi=10.1055/s-2007-994131 |pmid=9259932 }}

Neonates born from women with consistently high blood sugar levels are also at an increased risk of low blood glucose (hypoglycemia), jaundice, high red blood cell mass (polycythemia) and low blood calcium (hypocalcemia) and magnesium (hypomagnesemia).{{Cite journal |vauthors=Jones CW |date=September 2001 |title=Gestational diabetes and its impact on the neonate |journal=Neonatal Network |volume=20 |issue=6 |pages=17–23 |doi=10.1891/0730-0832.20.6.17 |pmid=12144115 }} Untreated GDM also interferes with maturation, causing dysmature babies prone to respiratory distress syndrome due to incomplete lung maturation and impaired surfactant synthesis.

Unlike pre-gestational diabetes, gestational diabetes has not been clearly shown to be an independent risk factor for birth defects. Birth defects usually originate sometime during the first trimester (before the 13th week) of pregnancy, whereas GDM gradually develops and is least pronounced during the first and early second trimester. Studies have shown that the offspring of women with GDM are at a higher risk for congenital malformations.{{Cite journal |vauthors=Allen VM, Armson BA |date=November 2007 |title=Teratogenicity associated with pre-existing and gestational diabetes |journal=Journal of Obstetrics and Gynaecology Canada |volume=29 |issue=11 |pages=927–934 |doi=10.1016/s1701-2163(16)32653-6 |pmid=17977497 |author19=Society of Obstetricians Gynecologists of Canada}}{{Cite journal |vauthors=Martínez-Frías ML, Frías JP, Bermejo E, Rodríguez-Pinilla E, Prieto L, Frías JL |date=June 2005 |title=Pre-gestational maternal body mass index predicts an increased risk of congenital malformations in infants of mothers with gestational diabetes |journal=Diabetic Medicine |volume=22 |issue=6 |pages=775–81 |doi=10.1111/j.1464-5491.2005.01492.x |pmid=15910631 }}{{Cite journal |vauthors=Savona-Ventura C, Gatt M |date=August 2004 |title=Embryonal risks in gestational diabetes mellitus |url=https://www.um.edu.mt/library/oar//handle/123456789/31614 |journal=Early Human Development |volume=79 |issue=1 |pages=59–63 |doi=10.1016/j.earlhumdev.2004.04.007 |pmid=15449398}} A large case-control study found that gestational diabetes was linked with a limited group of birth defects, and that this association was generally limited to women with a higher body mass index (≥ 25 kg/m²).{{Cite journal |vauthors=Correa A, Gilboa SM, Besser LM, Botto LD, Moore CA, Hobbs CA, Cleves MA, Riehle-Colarusso TJ, Waller DK, Reece EA |date=September 2008 |title=Diabetes mellitus and birth defects |journal=American Journal of Obstetrics and Gynecology |volume=199 |issue=3 |pages=237.e1–9 |doi=10.1016/j.ajog.2008.06.028 |pmc=4916956 |pmid=18674752}} It is difficult to make sure that this is not partially due to the inclusion of women with pre-existent type 2 diabetes who were not diagnosed before pregnancy.{{cn|date=January 2025}}

Because of conflicting studies, it is unclear at the moment whether women with GDM have a higher risk of preeclampsia.{{Cite journal |vauthors=Leguizamón GF, Zeff NP, Fernández A |date=August 2006 |title=Hypertension and the pregnancy complicated by diabetes |journal=Current Diabetes Reports |volume=6 |issue=4 |pages=297–304 |doi=10.1007/s11892-006-0064-1 |pmid=16879782 }} In the HAPO study, the risk of preeclampsia was between 13% and 37% higher, although not all possible confounding factors were corrected.

The prevalence of GDM was 14.7%, 9.9%, and 14.4% in low-income countries (LIC), middle-income countries (MIC), and high-income countries (HIC) in 2021 by International Association of Diabetes in Pregnancy Study Group's criteria.{{cite journal |last1=Wang |first1=Hui |last2=Li |first2=Ninghua |last3=Chivese |first3=Tawanda |last4=Werfalli |first4=Mahmoud |last5=Sun |first5=Hong |last6=Yuen |first6=Lili |last7=Hoegfeldt |first7=Cecilia Ambrosius |last8=Elise Powe |first8=Camille |last9=Immanuel |first9=Jincy |last10=Karuranga |first10=Suvi |last11=Divakar |first11=Hema |last12=Levitt |first12=NAomi |last13=Li |first13=Changping |last14=Simmons |first14=David |last15=Yang |first15=Xilin |title=IDF Diabetes Atlas: Estimation of Global and Regional Gestational Diabetes Mellitus Prevalence for 2021 by International Association of Diabetes in Pregnancy Study Group's Criteria |journal=Diabetes Research and Clinical Practice |date=January 2022 |volume=183 |pages=109050 |doi=10.1016/j.diabres.2021.109050 |pmid=34883186 }}

By 2021, the Global prevalence of hyperglycemia in pregnancy (HIP) as per the IDF atlas will be 21.1 million people, accounting for 16.7% of births to women aged 20-49. These individuals may experience some form of hyperglycemia during pregnancy; 80.3% of these were due to GDM.{{cite journal | url=https://doi.org/10.62996/daj.09072024 | doi=10.62996/daj.09072024 | title=Epidemiology of Gestational Diabetes Mellitus: Newer Evidence to curtail | date=2024 | journal=Diabetes Asia Journal | volume=1 | pages=60–65 | vauthors = Jain R, Seshiah V, Jain G }}

{{Reflist}}

{{Medical resources

| DiseasesDB = 5195

| ICD10 = {{ICD10|O|24||o|20}}

| ICD9 = {{ICD9|648.8}}

| ICDO =

| OMIM =

| MedlinePlus = 000896

| eMedicineSubj =

| eMedicineTopic =

| MeshID = D016640

}}

• [https://diabetesatlas.org/ IDF Diabetes Atlas]
• [https://www.idf.org/ International Diabetes Federation]
• National Institute of Child Health and Human Development – [https://web.archive.org/web/20061002024933/http://www.nichd.nih.gov/publications/pubs/upload/gest_diabetes_risk_2005.pdf Am I at Risk for Gestational Diabetes?]
• National Institute of Child Health and Human Development – [https://web.archive.org/web/20080829230647/http://www.nichd.nih.gov/publications/pubs/gest_diabetes/ Managing Gestational Diabetes: A Patient's Guide to a Healthy Pregnancy]
• Gestational Diabetes Resource Guide – [https://web.archive.org/web/20071229021412/http://www.diabetes.org/gestational-diabetes.jsp American Diabetes Association]
• Diabetes.co.uk: [https://www.diabetes.co.uk/gestational-Diabetes.html Gestational Diabetes]

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

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

{{Diabetes}}

{{Authority control}}

{{DEFAULTSORT:Gestational Diabetes}}

Category:Types of diabetes

Category:Health issues in pregnancy

Category:Women's health

Category:Wikipedia medicine articles ready to translate