What is AMH?
AMH is a hormone that, in women, is produced by cells called “granulosa cells”, which surround the follicles (fluid collections that contain the eggs in the ovaries). In the field of Reproductive Medicine, AMH is considered a measure of a woman’s ovarian reserve, which refers to the number of eggs that remain in the ovaries and potentially egg quality as well.
How and when is a woman’s AMH level checked?
Since AMH produced by ovarian cells is secreted into the peripheral bloodstream, a woman’s AMH level can be checked with a blood test. An AMH level can be checked on any day of the menstrual cycle since it is a relatively stable hormone.
What patient factors can result in a falsely low AMH level?
Until recently, it was thought that birth control pills do not affect AMH test results and that a woman on birth control pills could have a blood test for AMH that would show accurate results. A study was published on this subject in April 2013 in the journal Fertility & Sterility, showing that AMH levels are indeed affected if a woman has been taking birth control pills for over 9 weeks. In this scenario, the AMH test result may be inaccurate and show a low AMH level that is false and may be significantly higher if the woman were not taking birth control pills. In order for the AMH test to be accurate after the discontinuation of birth control pills, a woman who has been taking birth control pills should stop taking the pills for at least 7 days prior to having an AMH level drawn. A recent study also showed that the medication Lupron, used at a dose for the temporizing treatment of endometriosis or uterine fibroids, can affect AMH test results as well.
AMH as a tool for individualizing IVF cycles for couples
AMH has been shown to predict ovarian response to medications that stimulated follicular growth during IVF cycles. High AMH levels are predictive of high oocyte yield. In these cases, a Gonadotropin Releasing Hormone (GnRH) Antagonist protocol and low-dose gonadotropins (the fertility injections that grow follicles during IVF) may be used in order to minimize the risk of severe ovarian hyperstimulation syndrome. Low AMH levels predict low oocyte yield and, in the cases of suboptimal ovarian response where only a few eggs may grow, higher dosages of gonadotropins are typically recommended in order to try to grow more eggs. In other words, there is a linear correlation between AMH level and oocyte yield and IVF medication protocols can be designed specifically for a patient based on her age, AMH levels, and prior ovarian response (if she has used fertility medications for ovulation induction or IVF before) to fertility medications.