What is AMH?
Anti-Müllerian Hormone (AMH) is produced by the antral (small) follicles growing in the ovary. It can be measured in a blood test.
The level of AMH reflects how many follicles are growing, which gives an indication of how many eggs are present in the ovary. The more follicles that are growing, the higher the level of AMH in the blood AMH does not tell you about the quality of your eggs.
Certain factors may affect AMH levels. In particular, if you have polycystic ovaries (PCO), more small follicles are growing in your ovaries, In this situation, your levels of AMH may be elevated.
AMH testing is used during IVF to to optimise and individualise your stimulation schedule, giving you the best chance of achieving optimal stimulation. A low number of growing follicles, for example due to previous illnesses and pelvic operations, chemotherapy or because you are approaching the menopause, can be identified through low AMH levels and adapt your dosage of gonadotrophins to try to compensate.
What are the pros and cons of AMH testing?
During IVF Research has shown that AMH measurement is the most reliable method of predicting the likely response of the ovary, (better than other tests that you might have heard of, such as FSH or inhibin)
The benefits are that it improves the doctor’s ability to prescribe the best individualised stimulation regime for your personal needs. In this way, your treatment can be optimised giving you the best chance of achieving a successful outcome. During fertility treatment it is recommend that you have it done, especially if you are in one of the following situations: Previous poor response, Older women (age>35) or If you have ever had a high FSH or a high E2 blood test result.
Low AMH and positive fertility Outcomes
- a trial in Copenhagen found that AMH levels didn’t relate to the time taken to conceive in natural conception. Natural pregnancy was still possible with undetectable AMH
- an American study found that women with low AMH (<0.7 ng/mL) didn’t have a statistically different likelihood of conceiving within 6 months than women with normal levels
- AMH levels related to the number of eggs retrieved, but not pregnancy rates in women over 40 in their first IVF cycles. Patients with extremely low AMH still had a chance of pregnancy
- AMH used to be regarded as a predictor of how long a women has before menopause. A recent review shows that the rate of decline in AMH varies between women so AMH isn’t a reliable predictor. The review also states AMH to be a poor predictor of pregnancy in natural or assisted conception
The Importance of AMH testing
While AMH may not be as reliable as first thought it’s still an extremely useful part of decision making.
- AMH is the best current available blood test measure of ovarian reserve
- AMH is the best predictor of IVF success in antagonist cycles
- higher AMH levels are associated with higher pregnancy rates for women under 40 undergoing IVF
- AMH and antral follicle count are the most sensitive indicators of ovarian reserve and medication dosage needed during IVF cycles, and help personalise the IVF cycle to the patient
- AMH was more reliable at predicting eggs retrieved and live birth rate after IVF when the AMH level and antral follicle count didn’t seem to agree
- AMH may be useful in assessing diminished ovarian reserve in women with autoimmune thyroid disease