The "rabbit test" refers to the late 1920s method of injecting a woman's urine into a female rabbit to detect pregnancy. Within several days of doing the rabbit test, the rabbit's ovaries will show changes if the female is pregnant. The changes occur due to the presence of human chorionic gonadotropin (hCG), which is a hormone that occurs in the uterus when a woman's egg is fertilized.
The expression "the rabbit died" was commonly used to mean that a woman was given a rabbit test and found to be pregnant. However, while popular, the term is incorrect as the rabbit died regardless of whether the woman was found to be pregnant or not. The animals had to be sacrificed to examine the ovaries. The rabbit test was later revised so that ovarian changes could be checked in live, rather than dead, rabbits.
Blood tests and urine pregnancy tests at home replaced the rabbit test. Both methods also test for hCG in the body, but they don't use rabbits at all. Unlike the other methods, the rabbit test is a type of bioassay, or animal type.
Dr. Maxwell E. Lapham was one of the medical researchers who worked on the development of the rabbit test. He was director of the Medical Outreach Division and later dean emeritus at Tulane University School of Medicine in New Orleans, Louisiana, United States. Dr. Lapham died in 1983 at the age of 83.
The rabbit test is also known as the Friedman test after Maurice H. Friedman. Friedman, a German, was the first person to use rabbits for pregnancy tests. Friedman developed his rabbit test from the first pregnancy test, the Aschhiem-Zondek, used on mice.
The Aschhiem-Zondek pregnancy test was invented by the Germans Selmar Aschheim and Bernhard Zondek. It was Zondek who first discovered the hormone hCG in pregnant women. The Friedman rabbit test was found to be more accurate than Aschheim-Zondek pregnancy tests performed on mice. The German word for pregnancy tests is Schwangerchafttests while "rabbit test" in German is Kaninchentest .