AMH: what it does and doesn't tell you

What AMH is

Anti-Müllerian hormone (AMH) is made by small, growing follicles in the ovaries. Each follicle is a tiny fluid-filled sac that holds an immature egg. Because the number of follicles falls with age, AMH gives a rough estimate of ovarian reserve: how many eggs remain.

AMH is a simple blood test, and it can be done on any day of the cycle. It is one of two common ways to estimate ovarian reserve. The other is the antral follicle count, where follicles are counted on an ultrasound scan early in the cycle.

How results are reported

Laboratories report AMH in either pmol/L or ng/mL. These are different units, so the same result can look like a very different number. As a rough guide, 1 ng/mL is about 7.1 pmol/L.

Different laboratories also use different test methods, and their ranges are not always the same. Always use the range printed on your own report, and compare results from the same laboratory where possible. Many reports show ranges for different ages, because AMH naturally falls over time.

What it is useful for

• Planning treatment. AMH helps a doctor predict how the ovaries may respond to stimulation medicines in IVF or egg freezing, and plan the treatment accordingly.
• Egg freezing conversations. Alongside age, it can give a rough idea of how many eggs might be collected in a cycle.
• Context for planning. It can inform conversations about timing, together with your age and your scan.

What it doesn't tell you

Good to know. A low AMH does not mean you cannot get pregnant, and a high AMH does not mean you will.

Question	Can AMH answer it?
Roughly how many eggs remain	It gives an estimate
How the ovaries may respond to IVF medicines	It helps predict this
How good the eggs are	No
Whether you will conceive naturally in the coming months	No, this hasn't been shown
The exact age you will reach menopause	No, not with any precision
Whether you have PCOS	Not on its own

AMH reflects quantity, not the quality of eggs. Egg quality is closely linked to age. This is why a younger person with a low AMH and an older person with the same result may be in quite different situations.

In a well-known study of women aged 30 to 44 who were trying to conceive without treatment, those with low AMH were not less likely to conceive in the following months than those with normal AMH.

Things that can affect the result

• Hormonal contraception, such as the combined pill, can lower AMH for a while. Tell your doctor if you are using it, or stopped recently.
• Surgery on the ovaries, for example for endometriosis cysts, can lower AMH.
• Pregnancy and some medical treatments can lower it.
• Smoking is linked with lower AMH.
• Polycystic ovary syndrome (PCOS) often makes AMH higher.
• The laboratory and test method, as described above.

Higher AMH and PCOS

AMH is often higher in people with PCOS, because they tend to have more small follicles. The 2023 international PCOS guideline allows AMH to be used in adults in place of an ultrasound for the "polycystic ovaries" part of the diagnosis. Even so, a high AMH is not a diagnosis of PCOS on its own. Other signs, such as irregular periods, need to be present too.

Should you test AMH "just to know"?

AMH tests are widely available in India, sometimes without a doctor's request. Professional societies, including the American Society for Reproductive Medicine, advise that ovarian reserve tests such as AMH should not be used on their own to predict whether someone can conceive.

If you are not trying yet and want to understand your fertility, it is more useful to have the test as part of a conversation with a doctor, who can explain the result alongside your age and health.

Caution. A single AMH result should not be the only reason to rush into treatment. If you feel pushed, ask how the result fits with your age, your scan and your history, and consider a second opinion.

When to see a doctor

• You have an AMH result and are unsure what it means for you.
• Your AMH is low and you are thinking about when to try, or about egg freezing.
• You have been trying for 12 months (under 35) or 6 months (mid-30s and over), whatever your AMH.
• Your periods have become irregular, or stopped, before your mid-40s.

It is worth discussing your result with a doctor rather than relying on the number alone. Our appointment question builder can help you prepare.