Anti-Müllerian Hormone (AMH) and Infertility
The role that low anti-mullerian hormone (AMH) plays in female infertility is discussed by Dr. Norbert Gleicher and Dr. Vitaly A. Kushnir from the Center for Human Reproduction in New York, NY. Here, the following questions are discussed: What is AMH’s physiological role in female reproduction? What is the difference between follicle-stimulating hormone (FSH) and AMH? How are normal AMH levels defined? What are the implications of low AMH levels? Can women get pregnant with very low AMH levels? Can AMH levels be improved? What is good advice for women with very low AMH levels?
AMH is a little bit more of a complex issue than that because AMH is a response to a number of different things, but probably most importantly, a response to how much follicles, or how aggressively follicles are being recruited into maturation from their dormant state as primordial follicles into the active maturation stage. If that process is very active, and a lot of follicles 0:59 are starting to journey towards maturation, AMH goes up and holds back further recruitment,and therefore in older women where there’s already very little recruitment going on, AMH is getting lower and lower and lower. But when AMH is high it usually means that it is holding back recruitment meaning that there is still lots of follicles there to be recruited and to go into maturation. AMH is a more direct reflection of what’s happening in the ovary because AMH is secreted by the antral and pre-antral follicles that are developing within the ovary. The more of those follicles there are, the higher the AMH levels. FSH is the signal that the brain sends to the ovary to try to increase, steer ootidogenesis and production of follicles in the ovary so FSH levels are actually elevated in women who have few follicles, and low or normal in women who have many follicles in their ovaries. FSH and AMH interact within the ovary in that FSH, or AMH actually, holds back the recruitment of primary follicles by FSH. The normal AMH level is dependent on the woman’s age; and for example somebody who is in her 30s, like many of our egg donors are, their AMH level should be about 4 nanograms/ml; whereas somebody who is older, for example woman in her mid-30s, a normal level can be a bit lower, maybe 2.5; and somebody who is in their 40s can have an even lower AMH level than this. So it’s important to view AMH is context of a patient’s age to determine what is normal for the individual. Low AMH levels reflect the number of antral and pre-antral follicles that are available in the ovary. This is not a perfect predictor of somebody’s fertility potential but it gives us a rough idea of how many eggs and embryos we might be able to get with fertility treatment or with IVF. Yes, we’ve seen women with even undetectable levels of AMH getting pregnant, just because we can’t measure the AMH level it doesn’t mean there are no eggs left in the ovary, it just means there are fewer of them there, but women do get pregnant with even undetectable levels of AMH, particularly younger women have a much better chance if their AMH levels are low compared to older women. So we think that functional ovarian reserve and AMH levels can be improved and CHR has done some investigation in this area and we’ve found that DHEA supplementation can help improve AMH levels and the functional ovarian reserve. Well one of the main things to think about is first of all, are there underlying causes for having this low AMH, so we do a very thorough investigation before we embark on fertility treatment to figure out if there are reasons for why somebody’s AMH level is abnormally low because there may very well be genetic reasons or medical reasons that pre-dispose them to develop those AMH levels in the first place. Some of those medical conditions can put them at risk for miscarriages or various pregnancy related problems if they’re not identified and appropriately treated. Well the most important thing I tell my patients is not to delay appropriate investigation and treatment because in most women with pre-mature ovarian aging, which is evidence by low AMH levels, the situation only gets worse with time, it doesn’t get better. So the most important thing is not to delay appropriate investigation and treatment.