What Is Your Number?...An Intro To Ovarian Reserve Testing

Jason Yeh, MD
February 3, 2021
What Is Your Number?...An Intro To Ovarian Reserve Testing

What’s Your Number?

It’s normal for a woman to be curious about her ovarian health and wonder if she will have difficulty getting pregnant in the near or distant future. While it isn’t an easy question to answer, there are several tests that can help patients and doctors predict whether a woman has a biological clock that is ticking slower or faster than expected. To help women better plan for their future, testing is available to provide them with helpful information about ovarian reserve.

What is AMH?

Anti-mullerian hormone, or AMH, is a hormone that does many different things and has important functions in both men and women. As a fertility specialist, AMH helps me every day because it gives me a small snapshot of a woman’s ovarian health. This is because AMH is secreted by important cells in the ovary throughout the reproductive years of a woman’s life. Since women are born with all the eggs they will ever have, and the number of eggs for each woman decreases until menopause, AMH levels are expected to slowly decrease as a woman’s age increases.

Why is this recommended and what does this test tell me?

Checking your AMH is important because it is similar to “checking how much gas is left in the tank.” Since we know what normal AMH values are for a woman in her 20s, 30s and 40s, we can measure each woman’s fertility by comparing her AMH to her expected AMH value for her age. In women above age 30, AMH is actually quite good at predicting pregnancy rates for couples who are trying to conceive naturally.

But doesn’t fertility have more to do with age and normal cycles?

That’s only partially true. For most women, age is the easiest way to predict the chance of getting pregnant each month since there’s no blood or medical testing involved. However, a woman’s body is very complicated and every woman has unique ovarian characteristics so age isn’t always the most precise way to measure fertility. There are many young women, for example, who have regular menstrual cycles and who have a biological clock that is ticking faster than normal. These women are at risk of losing their fertility sooner than expected and can be easily identified with the AMH blood test.

What does this mean for a woman’s fertility options?

It’s really important to remember that AMH is not a perfect test. In fact, there are multiple other ways to check ovarian reserve such as measuring follicle stimulating hormone (FSH). Another way is for a physician to perform an ultrasound where the number of antral follicles on each ovary are counted (AFC). NO one test is considered the best, so whenever possible, I like to obtain multiple measures or tests to give patients a more complete description of their reproductive health.

Once a patient with true low ovarian reserve is identified, there is usually an improvement in fertility once treatment is started. Because fertility treatments have become so effective, some patients with low AMH can “overcome” this problem by using medications to improve ovarian function each month.

Does AMH tell us anything else besides fertility?

Absolutely. AMH levels that are very high or very low can hint at other problems that are important to identify and treat.

For patients who have AMH values that are very high, or “off the charts”, I tell them that it is very likely that they were born with many more eggs than the average female. While this may sound like a good thing, women with very high AMH levels commonly have irregular menstrual cycles and should be screened for polycystic ovarian syndrome (PCOS). PCOS is an important diagnosis to make because, in addition to problems with fertility, there are serious metabolic and health implications that can persist for 5, 10 and even 30 years if not properly addressed.

Conversely, patients with very low AMH may have other underlying issues that have caused their ovarian reserve to prematurely fall. Because the ovaries are involved in many other functions outside of fertility (such as cardiovascular, bone, mental health, etc.), identifying women with abnormally low ovarian reserve is important.

Jason Yeh, MD

Jason Yeh, MD

Dr. Jason Yeh completed his residency and subspecialty training in infertility at Duke University. He is a born and raised Texan who graduated from the Plan II Honors Program at the University of Texas at Austin. After college, he was awarded a tuition scholarship to attend the University of Texas Southwestern Medical Center at Dallas and went on to complete residency training in Obstetrics and Gynecology at Duke University Medical Center in Durham, North Carolina. There, he won multiple teaching and research awards, and was elected to serve as the administrative chief of the Duke Obstetrics and Gynecology Department, where he remained to complete his fellowship training in Reproductive Endocrinology and Infertility. Dr. Yeh has specialized interest in the relationship between dietary habits, irregular ovulation, fertility and polycystic ovarian syndrome (PCOS). Furthermore, Dr. Yeh has been invited to lecture nationally and internationally on topics ranging from women's health and infertility to technology in healthcare. In addition, his mission is to add to the tremendous talent already at Houston Fertility Institute as Director of Patient Education and care for patients using the most effective and up-to-date approaches in minimal stimulation ovulation induction techniques (“Mini-” or "Micro-Stim" IVF), advanced reproductive technology, preimplantation diagnosis/screening, and third party reproduction.

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