Rabbit test

{{Short description|Pregnancy test}}

{{Other uses|Rabbit Test (disambiguation){{!}}Rabbit Test}}

{{redirect|Dead rabbit|the 19th-century New York gang|Dead Rabbits|the American band|The Dead Rabbitts}}

{{for|the statistical test|Friedman test}}

{{Use dmy dates|date=May 2025}}

The rabbit test, or Friedman test, was an early pregnancy test that required killing and dissecting a rabbit to obtain the results. The test was developed in 1931 by Maurice Friedman and Maxwell Edward Lapham{{cite journal |journal=Journal of Endocrinology |volume=24 |issue=5 |date=1 May 1939 |title=The assay of gonadotropic extracts in the post-partum rabbit}} at the University of Pennsylvania.

Test

The hormone human chorionic gonadotropin (hCG) is produced during pregnancy and can be found in a pregnant woman's urine and blood; it indicates the presence of an implanted fertilized egg. An earlier test, known as the AZ test, was developed by Selmar Aschheim and Bernhard Zondek.{{cite encyclopedia |editor=Morris Fishbein, M.D. |encyclopedia=The New Illustrated Medical and Health Encyclopedia |title=Aschheim-Zondek Test |edition=Home Library |year=1976 |publisher=H. S. Stuttman Co |volume=1 |location=New York |pages=139}} When urine from a woman in the early months of pregnancy was injected into immature female mice, their ovaries would enlarge and show follicular maturation. The test was considered reliable, with an error rate of less than 2%.{{cite journal |last=Evans |first=Herbert M. |author2=Simpson, Miriam E. |year=1930 |title=Aschheim-Zondek test for pregnancy – its present status. |journal=Calif West Med |volume=32 |issue=3 |pages=145–8 |pmc=1657362 |pmid=18741327}} Friedman and Lapham's test was essentially identical, but replaced the mouse with a rabbit. A few days after the injection, the animal would be dissected and the size of her ovaries examined.

The rabbit test became a widely used bioassay (animal-based test) to test for pregnancy. The term "rabbit test" was first recorded in 1949, and was the origin of a common euphemism, "the rabbit died", for a positive pregnancy test.{{Cite web|url= http://www.wordorigins.org/index.php/site/comments/rabbit_test_the_rabbit_died/ |archive-url= https://web.archive.org/web/20191102160831/http://www.wordorigins.org:80/index.php/site/comments/rabbit_test_the_rabbit_died/ |archive-date=2 November 2019 |title=rabbit test / the rabbit died |last=Wilton |first=Dave|date=28 February 2007 |website=www.wordorigins.org |access-date=30 July 2018}} The phrase was, in fact, based on a common misconception about the test. While many people assumed that the injected rabbit would die only if the woman was pregnant, in fact all rabbits used for the test died, as they had to be dissected in order to examine the ovaries.{{cite news|title=Dr Maurice Friedman 87 Dies Created Rabbit Pregnancy Test|last=Howe|first=Marvine|date=10 March 1991|newspaper=The New York Times|url=https://www.nytimes.com/1991/03/10/obituaries/dr-maurice-friedman-87-dies-created-rabbit-pregnancy-test.html}}

A later alternative to the rabbit test, known as the "Hogben test", used the African clawed frog, and yielded results without the need to cut the animal open.{{Cite news|url=https://www.theatlantic.com/science/archive/2017/05/how-a-frog-became-the-first-mainstream-pregnancy-test/525285/|title=How a Frog Became the First Mainstream Pregnancy Test|last=Yong|first=Ed|date=4 May 2017|work=The Atlantic|access-date=30 July 2018|language=en-US}} Modern pregnancy tests continue to operate on the basis of testing for the presence of the hormone hCG in the blood or urine, but they no longer require the use of a live animal.

References

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Sources

  • {{Cite Q|Q115596844}}