Developed in 1927 by Bernhard Zondek and Selmar Aschheim, the Rabbit Test was an early way to detect pregnancy.  Although the original test actually involved mice, the Rabbit Test was nonetheless an important transition for medical advances in the middle of the twentieth century.

In the test, a doctor injected the urine from a woman into a female rabbit.  A few days later, the doctor examined the rabbit’s ovaries, looking for changes in response the hormone secreted only in pregnant women. This hormone – human chorionic gonadotropin (hCG) – is produced during pregnancy and an indication of a fertilized egg. Before this time, scientists believed hCG was produced by the pituitary gland. Georgeanna Jones, however, discovered hCG was indeed produced by the placenta.

From the 1930s to 1950s, this particular examination became a widely used pregnancy test, and the actual term “rabbit test” was first recorded in 1949.  Indeed, Xenopus frogs were also used in a similar “frog test.” Modern pregnancy tests still use the same concepts to determine the presence of the hormone hCG. Advances in medicine, however, have eliminated the need to use live animals.

There is a common misconception that only if the woman was pregnant would the injected rabbit die, which led to the phrase “the rabbit died” (meaning a positive pregnancy test). Unfortunately, all rabbits used for this particular test died as all examinations of rabbit ovaries were through invasive surgical intervention. Although it was possible to perform the exam without compromising the bunny, at the time medical science was more concerned with the trouble and expense it would involve.

[audio:http://hospitalstay.com/wp-content/uploads/2011/01/11-Rabbit-In-Your-Headlights.mp3|titles=Rabbit In Your Headlights]