AMH is a protein hormone produced by the cells that directly surround the egg, called the granulosa cells.
Granulosa cells (GC) also produce the hormones estrogen and progesterone. Since the cells that surround each egg produce AMH, we can measure a patient’s blood AMH level and get a good determination of her total follicle pool or total egg count. If her AMH level is low, then her total follicle pool or egg count is also probably low. AMH offers additional insight into the patient’s ovarian reserve in complementing other tests such as serum day 3 FSH, day 3 estradiol, clomiphene citrate challenge testing (CCCT), or ovarian “antral” follicle count (AFC) using ultrasonography. Since cycle day 3 FSH levels often fluctuate widely, a single measure of FSH may not represent a patient’s true ovarian reserve especially if AMH and antral follicle count are normal.
The advantage of serum AMH testing is that AMH can be measured on any day of the patient’s menstrual cycle. In other words, its levels are cycle day independent, so patients don’t have to worry whether or not the blood sample is collected on day 3. Also, its levels tend to be more constant and more reliable for assessing ovarian reserve than day 3 serum FSH and estradiol. We often observe patients whose day 3 FSH and estradiol levels are normal, suggesting normal ovarian reserve, yet their AMH level is low and consistent with an observed low antral follicle count suggesting diminished ovarian reserve. Upon performing ovarian stimulation on such patients using gonadotropins, we often find that the AMH and antral follicle count properly identified the patient’s true ovarian reserve better than using serum day 3 FSH and estradiol measurements.
At Dominion Fertility, we place much more emphasis on AMH levels than we do on the other blood markers for ovarian reserve. In Europe, AMH is also the preferred biomarker for assessing ovarian reserve in many IVF centers but the use of AMH in the United States is becoming increasingly more popular.