Fertility Chronicles is proud to present a special blog series, “From the Fertility Experts,” where leading fertility experts answer commonly asked questions for patients about their fertility health and treatment options.We hope this series can help patients navigate their personal fertility journeys.—Catherine T. Yang, Editor, Fertility Chronicles
Univfy’s “Fertility Chronicles” guest blogger Dr. David Barad shares his advice on ovarian reserve tests. See Dr. Barad’s other blog posts on the topics "Antral follicles: How can I tell if my ovaries are functioning?" and "The ABC’s of Day 3 FSH."
Doctors have viewed anti-mullerian hormone (AMH) as a way to measure ovarian reserve for many years, but recently, its use has become more popular. The test is best seen as a gauge of how your ovaries will function in the context of fertility treatment and not necessarily as a measure of your natural fertility.
AMH is produced by ovarian follicles just before they are ready to start their final growth stage. At this stage, the follicles are less than six millimeters in diameter and are known as pre-antral and antral follicles. Larger follicles don’t produce significant amounts of AMH. Therefore, AMH can help determine your potential for response to ovarian stimulation over your next few menstrual cycles. AMH levels do not change much day-to-day in your cycle, so the blood can be drawn at any time.
Some factors, such as a recent pregnancy or certain hormonal contraceptives, can change your AMH report. These changes probably reflect true differences in the number of small antral follicles. For example, it can take two months after delivery of a baby for your menstrual cycles to resume. The reason: During a pregnancy, you have fewer antral follicles recruited, and therefore, fewer small follicles making AMH. For similar reasons, the use of hormonal birth control over several months can result in lower AMH levels than expected for your age.
AMH declines with age from your decreasing store of follicles. (This contrasts with Day 3 FSH, which rises as you get older.) If you are under age 38, your AMH will be between two and four nanograms per milliliter (ng/ml).[i] If you are age 40, your AMH is probably one ng/ml or less.
One problem with AMH testing is that today’s tests can’t detect AMH levels of less than 0.16 ng/ml. At our center, we have found that pregnancy is still possible even when AMH is less than one ng/ml, though pregnancy rates are reduced. Pregnancies are even possible with AMH in the undetectable range.
In general, if your AMH is greater than two ng/ml and less than four ng/ml, your ovarian function is probably normal. If your AMH is between one and two ng/ml, you may have a decreased ovarian response to treatment. If your AMH is less than one but is still detectable, you will have less potential response than most women and may need to be evaluated by a physician who has experience caring for women with very low AMH. If your AMH is undetectable and you are young, you may still have some chance, albeit very small, and should also be seen by an infertility specialist who is experienced in treating women with this problem.
If your AMH is higher than normal, you may be very sensitive to ovulation inducing medications. If you have a high AMH level, you should use less medication to decrease your risk of developing ovarian hyperstimulation syndrome, a painful condition in which your ovaries can get quite large and a lot of fluid is retained in your abdomen.
If your AMH is undetectable, your doctor is likely to offer IVF treatment; with donor eggs as an option. However, even if your AMH levels are undetectable, pregnancy, though not likely, is possible. The use of donor eggs in IVF is not limited by your biological clock. So, there is no reason to rush into a decision to use donor eggs until you’re comfortable that you’ve exhausted all possibility of pregnancy with your own eggs.
[i]If you live in Europe, AMH is measured in picomol per millileter (pmol/ml) . Multiply the nanogram per millileger (ng/ml) by 7.14 to get the equivalent European measurement