Anti-Mullerian Hormone

Also Known As

AMH

Mullerian-inhibiting hormone

MIH

Mullerian inhibiting factor

MIF

Mullerian-inhibiting substance

MIS

Formal Name

Anti-Müllerian Hormone

This article was last reviewed on

28 March 2023.

This article waslast modified on 28 March 2023.

At a Glance

Why Get Tested?

In the UK, measurement of anti-Müllerian hormone (AMH) has three generally accepted uses (based on published evidence):

To help guide treatment of women undergoing assisted conception procedures.
As part of an investigation of abnormal sexual development in babies and children.
AMH may also be used to monitor the response to treatment for some types of ovarian tumours.

When To Get Tested?

Some women are tested when they are referred for assisted conception procedures e.g. in vitro fertilisation (IVF). The result can help the doctor to provide appropriate treatment which is individualised to the patients' needs.

As part of an extended newborn screen, when an infant has ambiguous genitalia (i.e. it is not clear whether the baby is a boy or a girl).

AMH may be tested to monitor the response to treatment and tumour recurrence in women with an AMH-secreting ovarian tumour.

Sample Required?

A blood sample taken from the vein in your arm or from a heel prick in an infant

Test Preparation Needed?

No test preparation is needed

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

The test measures a hormone called anti – Müllerian hormone (AMH). This hormone is very important during the development of the male foetus as it is essential for the formation of male reproductive organs.

In males, AMH is generated within cells in the testes. AMH is detectable at birth in males and levels rise rapidly in infancy. After puberty, the levels of AMH decline in men.

In females, small amounts of AMH are produced by developing follicles in the ovaries. At birth and in childhood the level of AMH in girls is very low but increases significantly at puberty reaching a peak in early adulthood. As women age, the number of follicles (which produce AMH) decreases and so the level of AMH declines and becomes undetectable after the menopause. AMH levels in women therefore reflect the declining ovarian function, and its measurement is said to indicate ovarian reserve.

Common Questions

How is it used?

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.
When is it requested?
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.
What does the test result mean?

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.
Is there anything else I should know?

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.
1. Should every woman of child-bearing years have an AMH test?

No. AMH should only be requested by specialist doctors when a woman is undergoing assisted conception.
2. Should every male child have an AMH test?

No. AMH is only indicated when there are concerns about the sexual development of an infant or child.
3. Can an AMH test be performed in my doctor's surgery?

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).

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