Low ovarian reserve

What it means

Ovarian reserve is the number of eggs remaining in the ovaries. It is estimated with the AMH blood test and with an antral follicle count (AFC), a count of small follicles on a transvaginal ultrasound. Reserve falls with age in everyone, at different speeds in different women, and it can be reduced by surgery on the ovaries, for example for endometriomas (see endometriosis), and by some medical treatments, such as some cancer treatments.

Ovarian reserve is about quantity, not quality. Age predicts the chance of pregnancy more strongly than any ovarian reserve test.

What a low AMH does and does not predict

In a study published in JAMA in 2017 of women aged 30 to 44 without known fertility problems who were trying to conceive, those with a low AMH were not less likely to conceive naturally than those with a normal level. Guidelines therefore advise against using AMH to predict natural conception.

AMH and AFC are useful in fertility treatment: they predict how the ovaries are likely to respond to stimulation medicines in IVF, which helps to choose the dose and to set realistic expectations about the number of eggs. A low value is not, on its own, a reason to refuse treatment, and FSH measurement is not recommended as a predictor of response.

When testing is useful

• Before IVF, to plan the stimulation
• Before egg freezing, to estimate how many eggs a cycle may yield; the decision itself rests on age and plans
• After ovarian surgery or a medical treatment that may affect the ovaries
• As part of a fertility assessment; if you are 36 or over, NICE advises referral to a specialist without waiting a full year of trying

A test taken only to “check fertility” by a woman who is not trying to conceive cannot reliably tell her whether she will conceive naturally later.

Treatment planning with low reserve

In IVF, guidelines recommend adjusting stimulation to the predicted response. For women expected to respond poorly, the 2025 ESHRE guideline does not recommend very high doses of stimulation medicines or adding DHEA, and considers growth hormone and testosterone probably not recommended. ESHRE's review of add-ons found that most adjuncts and add-on treatments used alongside IVF are not supported by good evidence.

Testing embryos for chromosome number (PGT-A) is sometimes discussed when embryos are few. Current ESHRE and NICE guidance does not recommend it for routine use or to improve the chance of a live birth; your doctor can explain its limits in your situation.

When the chance of pregnancy is low, your doctor can discuss the options open to you.