Antimullerian Hormone (AMH) 

Anti-Müllerian Hormone (AMH) is a hormone produced by the granulosa cells of ovarian follicles in women. It plays a crucial role in the development and function of the reproductive system, particularly in the ovaries.

Indicator of Ovarian Reserve

AMH is used as a marker to estimate a woman’s ovarian reserve, which refers to the number of eggs remaining in the ovaries. Higher levels of AMH generally indicate a higher number of antral follicles and, therefore, a greater ovarian reserve. Conversely, lower AMH levels suggest a lower ovarian reserve.

Predicts Response to Fertility Treatments

In the context of assisted reproductive technologies (ART), such as in vitro fertilization (IVF), AMH levels can help predict how a woman will respond to ovarian stimulation. Women with higher AMH levels tend to produce more eggs in response to stimulation, while those with lower levels may produce fewer.

Involved in Follicular Development

AMH helps regulate the growth and maturation of ovarian follicles. It inhibits the excessive recruitment of follicles, helping to ensure that the ovaries release eggs in a controlled manner during each menstrual cycle.

Diagnosis of Polycystic Ovary Syndrome (PCOS)

Women with PCOS often have higher-than-normal levels of AMH, reflecting the increased number of small antral follicles in their ovaries.

Assesses Menopause Timing

AMH levels decline with age and become undetectable at menopause. Measuring AMH can provide insight into how close a woman is to menopause.

AMH levels are measured through a blood test. Unlike other hormones involved in the menstrual cycle, AMH levels remain relatively stable throughout the cycle, so the test can be done at any time.

The AMH blood test can be performed at any time during your menstrual cycle, and in most cases no special preparation is required. However, a few factors can help ensure your result is as accurate and clinically useful as possible.

Timing of the test

• AMH can be measured on any day of your cycle, including during your period or outside it.
• Unlike other fertility hormones, it does not need to be taken on day 2–5 of your cycle.
• Some fertility clinics may still prefer testing alongside other day 2–5 hormones for a full fertility profile.

Contraception and AMH testing

You do not need to stop contraception before having an AMH test.

However, it is important to understand the potential effects:

• Hormonal contraception (pill, implant, injection, hormonal coil) may cause a temporary reduction in AMH levels in some patients.
• This effect is usually mild and reversible after stopping contraception.
• If the result is unexpectedly low, some clinicians may recommend a repeat test around 2–3 months after stopping hormonal contraception for confirmation.
• Non-hormonal contraception (e.g. copper coil, condoms) does not affect AMH levels.

If you are under a fertility clinic

If you are currently under the care of a fertility specialist:

• You should check with your clinic before arranging or repeating an AMH test.
• Your fertility clinic may want AMH measured at a specific time alongside:
  • Day 2–5 hormone profile (FSH, LH, oestradiol)
  • Ultrasound antral follicle count (AFC)
• Results are best interpreted as part of a full fertility assessment rather than in isolation.

AMH reflects ovarian reserve, meaning the quantity of eggs remaining in the ovaries, but it does not provide information about egg quality. It is also not a standalone predictor of natural fertility or the likelihood or timing of conception. For this reason, AMH results should always be interpreted in context alongside a woman’s age, relevant medical history, ultrasound findings, and the overall fertility assessment.