A high AMH level means high egg quantity, but can occur with PCOS.
This is reflected in in vitro fertilization (IVF) cycles where AMH levels correlate nicely with the number of eggs that will be retrieved. Patients with low AMH levels (less than 0.6 ng/mL) will produce few eggs. Physicians will often use a higher dose of medication to stimulate these patients and try to maximize the number of eggs retrieved. On the other hand, patients with high AMH levels (greater than 3.5 ng/mL) will produce lots of eggs. High AMH levels are often seen in patients with polycystic ovarian syndrome (PCOS). These patients are at risk for ovarian hyperstimulation syndrome (OHSS) and are candidates for “gentle” stimulation during IVF.
Cycle day-3 follicle stimulating hormone (FSH) levels, on the other hand, predict the chances of conception with IVF. Every clinic should determine a level above which IVF pregnancy rates decrease (at InVia, our level is 10 mIU/mL) and a level above which the chance of pregnancy is less than 1% (20 mIU/mL at InVia).
Thus, AMH and FSH levels assess the “quantity” and “quality” of the eggs, respectively. They are often used together in combination with an antral follicle count, age and previous response to stimulation to assess ovarian reserve.
What if AMH level is "good" but and FSH is "bad" — or vice versa?
There are patients with reassuring AMH but concerning FSH level and others with reassuring FSH but concerning AMH level. What impact does this “discordance” have on a patient’s chances of success? The current belief is that the number of eggs retrieved decreases in the following order: reassuring FSH and AMH, concerning FSH but reassuring AMH, concerning AMH but reassuring FSH, and both concerning FSH and AMH.
Buyuk et al. (Fertil Steril 2011;95:2369-72) studied 73 women with elevated cycle day-3 FSH levels (> 10 mIU/mL). Women with elevated FSH who had a AMH level > 0.6 ng/mL, had twice the number of eggs retrieved, a greater number of day-3 embryos, a third of the cancellation rate, and a trend toward higher clinical pregnancy rates when compared with women with a AMH level <0.6 ng/mL. So a patient with a normal FSH level but low AMH level will probably do better than someone whose FSH level is high.
AMH levels vary throughout the menstrual cycle.
Sowers et al. from the University of Michigan at Ann Arbor (Fertil Steril 2010;94:1482-6) measured AMH levels throughout the menstrual cycles in 20 young volunteers. They described two distinct patterns of AMH secretion:
>An “aging ovary” pattern where the levels were less than 1 ng/mL and had minimal variation throughout the menstrual cycle.
>A “younger ovary” pattern where women had higher AMH levels and a significant variation in the first half of the cycle (follicular phase).
If the AMH level is below 1 ng/mL, then this is likely indicative of a constituently low level and decreased ovarian reserve. This interpretation could be made independent of the day of collection across the menstrual cycle. In contrast, interpretation of higher AMH levels will be dependent upon the day in which the specimen is collected within the menstrual cycle.
Kallio et al. (Fertil Steril 2013;99:1305-1310) measured AMH levels in 42 healthy women over a period of nine weeks. They measured five different hormones, including AMH. The levels did not change much at five weeks, but were significantly suppressed at 9 weeks. Please read my previous blog for details.
I have had women (who are not even trying to get pregnant) on birth control pills worried about a low AMH level. Some were told by their Ob/Gyn doctors to freeze their eggs immediately as they were running out of time. Egg donors (using birth control pills for contraception) are being rejected because of low AMH levels!
To get a more accurate level, these women need to be off the birth control pills for at least a cycle or two.
Low AMH level is NOT predictive of decreased chance of pregnancy in young healthy women.
I have written a blog discussing this fact in detail. At present, routine measurement of AMH level as a “fertility check” in young women is not useful.
Dr. Karande is Board Certified in the specialty of Obstetrics and Gynecology as well as the subspecialty of Reproductive Endocrinology and Infertility. He is a Fellow of the American College of Obstetricians and Gynecologists and Member of the American Society for Reproductive Medicine.