Understanding AMH Fertility Blood Test

The AMH test (Anti-Mullerian Hormone) is a blood test to help the fertility doctor assess the woman's ovarian reserve. The test measures the levels of AMH in a woman's blood and is helpful in determining whether a woman has premature ovarian aging (diminished ovarian reserve) or premature ovarian failure.

The Anti-Mullerian Hormone is a substance secreted by the granulose cells in the developing egg sacs (ovarian follicles). When a woman grows older, her number of ovarian follicles begins to decrease; therefore, the amount of AMH in the blood decreases.A woman who has very remaining follicles will have low AMH levels and is close to menopause. A woman who has many small ovarian follicles — a condition known as polycystic ovarian syndrome (PCOS) — typically has high levels of AMH.

Because AMH levels correlate with the number of ovarian follicles, the test is a good predictor of ovarian reserve. Researchers have found that women with higher concentrations of AMH have a better response to ovarian stimulation and are likely to produce more eggs for IVF (in vitro fertilization) than women with low or undetectable AMH. Also, unlike follicle stimulating hormone (FSH), the levels of AMH in the blood do not fluctuate as much; therefore the test can be done at any point during the menstrual cycle.

• A low AMH indicates there is a problem with the quantity and quality of a woman's eggs. Women with low AMH tend to be "poor responders" to fertility treatment — even with high doses of fertility drugs.
• High AMH levels correlate with low cancellation rates, retrieval of more eggs, higher live birth rates and a high chance for freezing of leftover embryos.
• Low AMH levels (alone) do not predict low IVF success rates in women under 35
• Couples should not be excluded from attempting IVF due to low AMH values alone because live birth success rates were reasonable in these cases

AMH is only one of the tests that assess ovarian reserve. Others include blood tests for FSH and estradiol levels, the clomiphene citrate challenge test (CCCT), and a vaginal ultrasound examination of the antral follicles.