by Dr. Anita Sadaty, GYN and Dr. Laura Paris, DACM
If you have trouble getting pregnant, or have asked your gynecologist for a test to find out about your egg quality, you may have heard about the AMH ovarian reserve test.
Clinicians and researchers have looked for a reliable way to figure out if you have good egg quality. The Anti-Mullerian Hormone (AMH) is a test currently available to check out your egg reserves, but it has some drawbacks. Here, we clarify what this test means for you if you are trying to get pregnant, if you want to know about your future fertility, and also what it means in regard to PCOS.
What you need to know about ovarian reserve
- There is no accepted universal definition of ovarian reserve.
- It is a confusing term because it can refer to your egg quantity, quality, or fertility potential – which are 3 different things.
- The number (quantity) of eggs you are born with are the only ones you will ever have. You don’t make new ones.
- With each menstrual cycle, your number of eggs drop. Not just one egg, because many more undergo development. Your number drops more rapidly after age 35.
- Once you’ve used up your egg supply, you go into menopause and your period stops.
- There is no way to precisely determine egg quality and quantity, we can only make a rough estimate.
- Ovarian reserve is used as short-hand for predicting your ability to get pregnant, but it’s not as straightforward as it sounds.
How does AMH relate to ovarian reserve?
AMH is made by the granulosa cells of your ovarian follicles (egg sacs). It indirectly reflects the total number of follicles in your ovaries. So, the lower your AMH level, the fewer follicles you have in reserve. The higher your level, the more follicles you have.
Women with fewer remaining follicles who are close to menopause or have premature aging of the their eggs have very low AMH levels (blood levels <1.0 ng/ml). In general, levels peak at age 25 and become undetectable 5 years after menopause.
What may not be clear is whether the total number of eggs available is the same as the quality of eggs that you have left. Quantity and quality are not the same thing. Keep this in mind.
What is a normal AMH level?
There are problems with interpreting AMH hormone levels. Because it is a relatively new test, “normal” levels are not agreed upon by most experts. aHere are values for 35-year-old woman:
- High (likely PCOS) = Over 4.0 ng/ml
- Normal = 1.5 – 4.0 ng/ml
- Low Normal = 1.0 – 1.5 ng/ml
- Low = 0.5 – 1.0 ng/ml
- Very Low = Less than 0.5 ng/ml
Don’t get carried away with the suggested cutoff values! In actual fact, there is very little clinical difference in fertility potential between a level of 1.0 and 0.9, even though that difference puts you in a different result box. In reality, these levels are part of a continuum and should not be taken alone to represent pregnancy potential.
What do studies say about AMH?
Studies are mostly about IVF, as that is the population most concerned with AMH levels.
- May identify women who won’t respond well to IVF “induction agents” (hormones that stimulate follicle growth for egg retrieval).
- Do NOT predict low IVF success rates in women under 35.
- May predict decreased success rates in older women, particularly over age 40.
High levels correlate with:
- Lower IVF cycle cancellation rates, meaning better chances that you can go through with implantation of fertilized embryos.
- A higher number of eggs retrieved per cycle, and higher live birth rates.
- Higher pregnancy rates with women of the same age (compared to low levels).
AMH does NOT tell your about the quality of the eggs in your reserve. This means that AMH levels correlate well with how many eggs you will make when stimulated with powerful IVF medications but it may not predict who will get pregnant with an IVF cycle.
AMH may be useful for older women, but not as useful as age
The test’s ability to predict pregnancy improves with older women. This is a very important point! We have many young women in our practices with low AMH test results who have been told they are infertile.
AMH levels are only weakly associated with egg quality as a stand alone test. Studies show that low AMH levels in your 20s does not mean that you are sub-fertile. Also, normal levels at age 40 may not mean you have adequate egg quality to achieve pregnancy.
Age alone is a more important predictor of fertility than AMH alone. The bottom line is that in the general population, AMH by itself does not tell you the full story.
Can AMH tell you if you have PCOS?
Yes, it’s a valid indicator of PCOS. Here’s why: Women with many small follicles, as in PCOS (polycystic ovarian syndrome) have unusually high AMH values. AMH levels are up to 3 times higher in women with early stage PCOS compared with normal controls.
A cut‐off level of 4.7 ng/ml is most accurate in diagnosing PCOS, particularly when viewed with other clinical signs and symptoms. AMH alone is not enough to diagnose PCOS, and is not part of the diagnostic criteria in the United States.
So what’s the AMH bottom line?
- Likely the most reliable marker of ovarian reserve in the setting of identifying good IVF responders.
- A useful tool in confirming a PCOS diagnosis.
- Better at predicting egg quality in older women (over 40) as compared to women under 40.
- Not accurate in predicting egg quality in women less than 30 as a stand alone measure.
- Not accurate as a stand-alone measure to determine fertility chances in women under 35.
- May not accurately predict your ability to get pregnant with IVF, and should not be used to exclude you from attempting IVF.
Don’t allow this single test to impact your thoughts about your fertility potential! If you are under 35 and have a low AMH level, consider working with a functional practitioner to optimize your chances of getting pregnant naturally or to help you improve your chances of pregnancy while undergoing IVF or other assisted reproductive techniques.
We very much welcome your questions and comments below,