Anti-Müllerian hormone (AMH): what it is, what it tells you and when it’s tested

Anti-Müllerian hormone, or AMH, is made by the small follicles in the ovaries, the sacs that hold the eggs. The more follicles there are, the more AMH. That is why it gives an idea of how many eggs are left, the so-called ovarian reserve. It falls with age and becomes very low after menopause.

When it’s tested

It is used mostly in fertility clinics, before ovarian stimulation or IVF: it helps predict how many eggs can be collected.

Doctors may also order it when they suspect polycystic ovary syndrome, where it is often high. For an early menopause, FSH is the main test; AMH only sometimes, when there is doubt.

It is not useful for people who feel well and want to know how fertile they are, because it does not answer that question. That is why Rosa does not test it. Instead it looks at what often weighs on your cycle: TSH for the thyroid, and insulin and blood sugar, which are worth watching in polycystic ovary syndrome.

What it tells you, and what it does not

AMH tells you, indirectly, how many eggs are left. It says nothing about their quality.

It does not tell you your chance of getting pregnant naturally. In a study of hundreds of women aged 30 to 44 with no known fertility problems who were trying for a pregnancy, those with a low AMH were as likely to get pregnant as the others. Age matters far more.

Nor does it tell you when menopause will come. A low AMH suggests it may come a little earlier than average, but for one woman the margin of error is too wide to give a date.

That is why it is read together with other tests:

Normal AMH levels

There is no single normal value. AMH is higher when you are young, falls over the years and is very low after menopause. Even between women of the same age, values vary a lot.

The numbers depend on the lab method and the unit: some labs use ng/mL, others pmol/L, which gives bigger numbers. Some reports print intervals by age group. Read your value against the interval on your own report.

Unlike FSH and oestradiol, AMH changes little through the cycle. You can have it done on any day.

If your AMH is low or high

AMH, pregnancy and menopause: what it cannot tell you

If you have no known fertility problems, AMH does not tell you whether you will get pregnant, or how long it will take. A low value is not a reason to give up, and a high one is not a guarantee.

In IVF it matters more: a low AMH predicts fewer eggs collected. Even there, it is not enough to say a pregnancy will not happen.

Over 45, AMH is not used to tell whether you are in perimenopause or menopause. Your symptoms and your periods are enough.

What can skew the result

A few things change AMH without changing how many eggs are left. It helps to know them before your blood test.

When to talk to a doctor

Talk to your doctor or gynaecologist if:

Frequently asked questions

Can you get pregnant with a low AMH? Yes. In studies, women with a low AMH and no known fertility problems got pregnant naturally as often as the others. Age matters more. If you have been trying for a while, talk to your gynaecologist.

What are normal AMH levels by age? AMH falls with age, but it varies a lot between women of the same age and from one lab to another. Use the interval printed on your report, and have a gynaecologist read it.

Does AMH tell me when I will reach menopause? Not precisely. A low AMH points to a menopause a little earlier than average, but the error for one woman is too large to give a date.

What does a high AMH mean? Often there are many small follicles, as in polycystic ovary syndrome. In adult women a high AMH can replace the ultrasound as one of the criteria, but on its own it does not make the diagnosis.

When is the AMH test done? On any day of the cycle. If you take the pill or another hormonal contraceptive, the value can be lower: tell your doctor.

Does Rosa test anti-Müllerian hormone? No. Rosa measures TSH, insulin and blood sugar, which say a lot about what weighs on your cycle. If your doctor wants AMH, they order it separately.

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