Anti-Mullerian Hormone

Anti- Müllerian hormone (AMH) is not a routinely available test but may be useful in specific circumstances.

AMH is sometimes requested in women about to undergo assisted conception procedures for example in vitro fertilisation (IVF). The result of the test can be used to guide the treatment used.

Levels of AMH are much higher in baby boys than in baby girls. Therefore, in babies born with ambiguous genitalia (i.e. it is unclear if the baby is male or female) then AMH may be measured to help decide the gender of the infant.

AMH may also be measured in male infants with undescended testicles to determine whether functional testicles are present.

Some types of ovarian tumours produce AMH, and so its measurement can be used to monitor the effect of treatment and to identify tumour recurrence.

An AMH blood test may be requested in the following circumstances: 

• When a woman has been referred for assisted conception procedures.
• During investigation of abnormal sexual development. AMH may be requested in the newborn period when an infant has ambiguous genitalia or in a male child with undescended testicles.
• When a woman has confirmed or suspected AMH-producing ovarian tumour
• Some clinicians may request AMH as part of the investigation of primary ovarian insufficiency (POI) or polycystic ovarian syndrome (PCOS). However, there is limited evidence for the benefit of measuring AMH in the investigation of these pathologies.

1. Women referred for assisted conception procedures:

A low blood AMH concentration suggests a low follicle count or ovarian reserve and that the woman may respond less well to ovarian stimulation, and an alternative protocol may be followed.

A high blood AMH concentration suggests that the woman has an adequate follicle count or ovarian reserve but may be more likely to have an excessive response to ovarian stimulation and an alternative protocol may be followed.

In no situation does AMH concentration reflect oocyte health or chances for conception.

2. Investigation of abnormal sexual development:

Levels of AMH are much higher in baby boys than in baby girls. Therefore, in an infant with genitals that are not clearly male or female (ambiguous genitalia), the blood AMH concentration can be compared to expected concentrations to help determine the sex of the infant.

In a male child with undescended testicles, a low blood AMH concentration suggests that the testicles have not developed properly. However, a blood AMH concentration that falls within the expected range, alongside evidence from other investigations, indicates that the testicles are present and functional but not located in the usual position. 

3. AMH –producing tumours

Some specific ovarian cancers, commonly Granulosa cell tumours may produce AMH, and the concentration of AMH in the blood may then be used to help monitor response to treatment and to look for recurrence.

AMH is not detectable in all ovarian cancers.

4. Other uses of AMH

Low levels of AMH may be related to POI. High levels of the hormone may be due to PCOS. However, measuring AMH levels alone isn’t sufficient to make a clear diagnosis for POI or PCOS.

AMH is a relatively new diagnostic test. Some in the medical community may advocate its use for other clinical situations, (POI and PCOS – not discussed here in detail) however further evidence is required before these uses become accepted routinely in the UK.

No. AMH should only be requested by specialist doctors when a woman is undergoing assisted conception.

No. AMH is only indicated when there are concerns about the sexual development of an infant or child.

No. This test requires specialised equipment and must be performed in an accredited laboratory. Your blood sample may need to be sent to a reference laboratory (a laboratory experienced in performing the test and interpreting the result).