AMH Testing and What It Can Tell You
December 1, 2020
Hormones, hormones, hormones. You’re probably most familiar with ones like estrogen, insulin, progesterone, oxytocin, and testosterone. And if you’ve been pregnant, you may also be aware of human chorionic gonadotropin (hCG).
So anti-Mullerian hormone (AMH) might not be the most talked-about hormone — or even the most well-known related to reproductive health. But it’s certainly worth understanding, especially if you hope to get pregnant in the future.
Here, we take a deep dive into AMH, including:
- what AMH levels can tell you
- what AMH levels can’t tell you
- AMH’s relation to FSH and IVF
- how your doctor can use test results
Anti-Mullerian hormone or AMH is a hormone produced by the granulosa cells in your ovarian follicles. According to the American College of Obstetricians and Gynecologists (ACOG), the production of AMH is reflective of your ovarian reserve.
Think of your ovarian reserve as a basket of eggs. You’re typically born with a basket full of eggs, and those eggs get used up over your lifetime.
An AMH test can tell you your egg count. A low AMH level points to a diminished ovarian reserve (DOR) or low egg count, which is why the hormone is linked to fertility. In other words, if you have DOR, your basket of eggs is starting to empty out.
But here’s the kicker: Low AMH suggests DOR but isn’t definite. And also, AMH does not tell you if the eggs in the basket are good eggs.
Some doctors order an AMH level as a “fertility test.” But that’s problematic, precisely because AMH doesn’t tell the whole story.
That’s why the ACOG says this assessment shouldn’t be ordered for people who aren’t infertile to discuss their reproductive status and future fertility potential.
In fact, testing AMH if you’re younger than 35 and not diagnosed as infertile may cause unnecessary alarm, says Mark P. Trolice, MD, director of Fertility CARE: The IVF Center, and professor of obstetrics and gynecology at the University of Central Florida College of Medicine.
“While it’s possible the results of AMH screening may prompt people to electively freeze their eggs, extensive counseling on the true meaning of AMH levels is essential,” he explains.
If you’re looking for specific answers about natural fertility, AMH levels aren’t the place to look. “That’s because AMH doesn’t predict natural fertility in any accurate manner,” says Trolice.
However, if you’re undergoing in vitro fertilization (IVF), Trolice says AMH can be used to predict the number of eggs you may produce as well as the dosage of medication to stimulate egg production.
Jessica Scotchie, MD, REI, OB-GYN of Tennessee Reproductive Medicine, agrees. “In a non-infertile population, AMH levels don’t predict the time it will take to conceive, and they don’t predict infertility,” she says.
(We know “non-infertile” may sound like a tricky double negative, but it refers to people who aren’t trying to conceive and therefore have no proven difficulty.)
However, when used as part of an infertility workup, Scotchie says AMH can help doctors understand if the ovaries are aging more rapidly than they should and if there are fewer eggs remaining.
“AMH levels can also best predict how ovarian stimulations will progress when used in creating IVF protocols,” she says.
Currently, the best measure for determining ovarian aging, according to Trolice, is by combining your chronologic age, antral follicle count (AFC) on a sonogram (ultrasound), and AMH. AFC counts the number of small cysts on the ovary that represent eggs.
Since AMH reflects the number of eggs you have remaining in the ovary, Trolice says AFC and AMH are excellent guides to estimate the number (quantity) of eggs you have.
However, he does point out that your birthday is the best measure of the quality of eggs. “While both quantity and quality decline as you get older, age is the best indicator for your pregnancy chances,” he says.
Additionally, Trolice says the use of a screening test for diminished ovarian reserve in a population at low risk for DOR will yield a larger number of false-positive results.
That means labeling people as having DOR when many may, in fact, have a normal ovarian reserve. So he doesn’t recommend using AMH to predict fertility.
In other words, if 100 people in their 20s have their AMH level tested, and 15 of them get the DOR label as a result, it could cause undue stress among those 15 — when perhaps only a few of them will actually go on to have trouble getting pregnant.
Testing for your AMH level is a simple blood test. Since the measurement remains mostly stable throughout your cycle, your doctor can order a test at any time.
As a general guideline, the following levels (in nanograms per milliliter) represent the lower limit of serum AMH values by age:
- 45 years old: 0.5 ng/mL
- 40 years old: 1 ng/mL
- 35 years old: 1.5 ng/ mL
- 30 years old: 2.5 ng/mL
- 25 years old: 3.0 ng/mL
The above levels are considered conservative estimates, and the cutoffs also depend on the lab. Any results should be reviewed with the doctor who ordered the test.
According to Trolice, AMH levels below 1.6 ng/mL predict a smaller number of eggs retrieved with IVF. Levels below 0.4 ng/mL are severely low.
While test results are helpful, it’s also important to note that as you age, you have fewer eggs. This is normal! It means AMH levels decrease across the reproductive lifespan.
Follicle stimulating hormone (FSH) is made by your pituitary gland and is involved in sexual development and functioning. FSH stimulates the eggs in the ovary to grow, which causes estrogen and later progesterone to rise.
A higher FSH usually indicates low ovarian reserve, while a lower AMH indicates low reserve.
As with AMH, your doctor may order a test to find out your FSH levels in order to determine current ovarian reserve.
While FSH can be a helpful tool, most experts agree that AMH may be a more reliable predictor of ovarian reserve because the levels stay consistent throughout the menstrual cycle — and from cycle to cycle.
In general, Trolice says that the more eggs produced with IVF stimulation and retrieval, the greater likelihood for a reasonable number of good embryos to develop and transfer. (When eggs are fertilized by sperm, you get embryos. Not every egg retrieved will necessarily be fertilized successfully in IVF.)
“As a woman ages, the percentage of chromosomally abnormal eggs contributing to abnormal embryos increases. So, the lower the number of eggs retrieved, the less percentage of embryos,” he says. While lower AMH levels do lower IVF success, Trolice says this is more prominent in women in their late 30s and beyond.
To again use our egg basket analogy to explain quantity and quality: In your 20s and early 30s, you usually have more eggs — and more “golden” (good) eggs. In your later 30s and beyond, you usually have fewer eggs and fewer golden eggs.
But a young person with few eggs (low AMH) should still have a higher percentage of golden ones, and therefore better IVF success (more high-quality eggs retrieved) than an older person.
An older person can certainly luck out and have a lot of eggs left, but a higher percentage of those eggs will have lost their “golden status” through aging and may not result in normal embryos.
Scothchie points out that lower AMH levels (<1) are associated with:
- lower egg yield at retrieval
- higher risk of cycle cancellation (meaning your IVF cycle is canceled and your eggs aren’t retrieved)
- higher rates of abnormal fertilization
Unfortunately, there are no proven ways to increase your AMH levels.
But while you can’t increase your egg numbers (quantity), you can work to preserve egg quality by not smoking and maintaining a healthy weight as determined by your doctor. Both tobacco and obesity have been associated with lower egg quality.
Remember, even if you have fewer eggs, you can still have good ones — and that will increase your fertility success chances.
Other than determining your egg count, AMH levels may help your doctor with other medical conditions like polycystic ovary syndrome (PCOS) and menopause.
PCOS is one of the most common female hormonal disorders. But while many people with PCOS have elevated AMH levels, there’s no consensus by medical societies (such as the ACOG) to use AMH levels as diagnostic criteria for PCOS.
When it comes to predicting the start of menopause, the ACOG says the research on the role AMH levels play has given conflicting results.
There’s some evidence that AMH can be used as a general gauge but not as a definitive timetable. One recent study found that AMH measurement could help doctors estimate your final menstrual period.
Some people believe that AMH levels can help predict the gender of a baby, but Trolice says he knows of no evidence that AMH has any impact in determining the gender of a baby. “Male and female fetuses will produce different amounts of AMH during the pregnancy,” he says.
AMH levels help determine your ovarian reserve or the number of eggs you have at the time of testing. As you age, these levels decline. Doctors may order an AMH test as a diagnostic tool to help start a conversation about fertility. But AMH levels on their own can’t predict infertility.
If you have questions about your AMH levels or concerns related to fertility, it’s important that you talk to your doctor or a reproductive endocrinologist and infertility specialist.
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