The Abderhalden reaction is a now defunct blood test for pregnancy developed by Emil Abderhalden.

In 1909 Abderhalden found that on the discovery of a foreign protein in he blood, the body reacts with a defensive fermentation that causes disintegration of the protein. He developed the test in 1912. This test was apparently contentious soon after it's development and a significant body of work was published both in support of and refuting the its reliability. One such publication concluded "...the individual variations of both pregnant and non-pregnant sera make the results from both overlap so completely as ot render the reaction, even with quantitative technique, absolutely indecisive for either positive or negative diagnosis of pregnancy." The test's overall unreliability led to it's being superceded in 1928 by the Ascheim-Zondek test .

References

• B.G. Firkin & J.A.Whitworth (1987). Dictionary of Medical Eponyms. Parthenon Publishing. ISBN 1-85070-333-7
• Who Named It?

1. Van Slyke, Donald D.; Vinograd-Villchur, Mariam; and Losee, J.R. (1915). The Abderhalden Reaction. Journal of Biological Chemistry 23 (1), 377-406. experimental evidence of the unreliability of the Abderhalden pregnancy test