Getting pregnant in one’s 30s or 40s can come with uncertainties about the probability of conception and the length of time left before infertility sets in.
Fertility testing, measuring hormonal biomarkers of ovarian reserve, such as FSH, AMH and Inhibin B, has become a booming business targeting these women anxious about their dwindling prospects of getting pregnant. Women receiving a dreaded “diminished ovarian reserve” finding may rush into fertility treatment. On the other hand, a normal test result might lead a would-be-mum to delay planning a pregnancy.
Hormone values like AMH and FSH are often correlated with how well a woman would respond to IVF medications and predict how easily she would get pregnant through IVF. It was assumed, therefore, that they would also be good predictors of a woman’s natural fertility.
Increasingly, researchers are finding these tests meaningless for predicting whether a woman will conceive — at least in women who do not have a history of infertility. Acting solely on these ovarian test results, therefore, appears to be misguided.
In a paper published in 2015, researchers looked at AMH levels as a marker for predicting fertility and found no association.
A study published in JAMA in October 2017 also showed that Ovarian reserve tests are often of no value for many of these women.
In this study, 750 women aged 30 to 44 years with no history of infertility were tracked. Those women with “diminished ovarian reserve” were assumed to have greater difficulty getting pregnant, but it was found that there was no correlation between a woman’s egg count and her ability to conceive. Women with a low AMH value or a high FSH reading were no less likely to eventually become pregnant than women with a normal AMH level. Inhibin B measures were also not associated with fertility outcomes.
Before this study, many in the medical community thought it was plausible these tests could determine fertility. Whilst these tests are great measures of ovarian reserve, how many eggs you have, they don’t serve to predict a woman’s reproductive potential.
However, the conclusion of this study revealed that among the women attempting to conceive naturally, diminished ovarian reserve was not associated with infertility; women should be cautioned against using AMH levels to assess their current fertility.
Multiple factors determine fertility, for example, age, egg quality, uterine receptivity, hormonal and metabolic states, etc. Current ovarian reserve tests are of limited benefit in predicting natural fertility potential. Many women with a low ovarian reserve can achieve a natural pregnancy. It is not an uncommon occurrence to become pregnant with low or even undetectable AMH.