Rabbit test

For other uses, see Rabbit Test.

"Dead rabbit" redirects here. For the 19th-century New York gang, see Dead Rabbits. For the American band, see The Dead Rabbitts.

For the statistical test, see Friedman test.

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^[1] 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.^[2] 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%.^[3] 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.^[4] 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.^[5]

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.^[6] 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.

In the media

• Rabbit Test, a 1978 comedy film about the world's first pregnant man.
• "Sweet Emotion", a 1975 song by Aerosmith, contains the lyric "You can't catch me 'cause the rabbit done died."
• "What's Up, Doc?", an episode of the television series M*A*S*H which aired 30 January 1978 (S6 E20). A major plot point is Hawkeye managing to conduct a rabbit test to determine if Margaret is pregnant without killing Radar's pet rabbit.
• "Emancipation", an episode of the television series House, M.D. (s5, ep.8). The test is mentioned at the beginning of the episode, with House saying: "... a pregnancy test only takes five minutes and we no longer kill rabbits".

References

1. "The assay of gonadotropic extracts in the post-partum rabbit". Journal of Endocrinology. 24 (5). 1 May 1939.
2. Morris Fishbein, M.D., ed. (1976). "Aschheim-Zondek Test". The New Illustrated Medical and Health Encyclopedia. Vol. 1 (Home Library ed.). New York: H. S. Stuttman Co. p. 139.
3. Evans, Herbert M.; Simpson, Miriam E. (1930). "Aschheim-Zondek test for pregnancy – its present status". Calif West Med. 32 (3): 145–8. PMC 1657362. PMID 18741327.
4. Wilton, Dave (28 February 2007). "rabbit test / the rabbit died". www.wordorigins.org. Archived from the original on 2 November 2019. Retrieved 30 July 2018.
5. Howe, Marvine (10 March 1991). "Dr Maurice Friedman 87 Dies Created Rabbit Pregnancy Test". The New York Times.
6. Yong, Ed (4 May 2017). "How a Frog Became the First Mainstream Pregnancy Test". The Atlantic. Retrieved 30 July 2018.

Sources

• Friedman, Maurice H.; Lapham, Maxwell E. (March 1931). "A Simple, Rapid Procedure for the Laboratory Diagnosis of Early Pregnancies". American Journal of Obstetrics and Gynecology. 21 (3): 405–410. doi:10.1016/S0002-9378(16)42174-5. ISSN 0002-9378. Wikidata Q115596844.

External links

• Aschheim-Zondek pregnancy reaction at Who Named It?
• The Rabbit Test at Snopes
• The demand for pregnancy testing: The Aschheim–Zondek reaction, diagnostic versatility, and laboratory services in 1930s Britain, pages 240–241
• An early U.S. pregnancy test involved sacrificing rabbits at The Washington Post