At-home fertility tests may be a little too stringent when it comes to assessing fertility hormone levels in women, according to a study from researchers at the University of North Carolina at Chapel Hill that found current versions of at-home fertility tests may mistakenly label many women as infertile, based on incomplete hormone information and inaccurate cutoffs when measuring levels of follicle stimulating hormone (FSH).
In the study, presented October 26, 2010, before an annual meeting of the American Society for Reproductive Medicine, researchers measured FSH levels in a group of 100 women. Recreating the conditions and guidelines used in current at-home fertility tests, they found that a quarter of the women had abnormal FSH levels and would be deemed infertile. But when the researchers followed these women for six months, they found that they did not have more difficulty getting pregnant than the others in the study. However, when they raised the threshold of these tests to a higher value of the hormone, they did find an association with infertility.
"So it may be that this test can pinpoint infertility, but we need to uniquely define where that cutoff is going to be," says lead study author Dr. Anne Z. Steiner, assistant professor of obstetrics and gynecology at UNC.
Researchers found that antimullerian hormone (AMH), considered the sister hormone to FSH, was vastly superior at predicting fertility. Unfortunately, as the study notes, AMH can only be measured in the blood and not the urine, and even the blood test has not been approved for use. But Steiner predicts that, with more study, the use of this other hormone may provide a more accurate infertility test.
"That is not to say that [currently available] fertility tests are useless, but they certainly warrant further investigation," says Dr. Steiner. "Our findings may mean that we need to go back to the drawing board and change the potential cutoff for infertility in the current tests, or perhaps we need to explore other tests altogether."