Anti-Müllerian Hormone

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

AMH is a hormone produced by reproductive tissues. Its role and the amount normally present varies depending upon sex and age. (See the "What is being tested?" section for more on this.)

AMH test in women:
Women of childbearing age may have an AMH test ordered along with other hormone tests, such as estradiol and FSH, to estimate the remaining time left to conceive (ovarian reserve). These tests are also useful in evaluating ovarian function and possibly in predicting the onset of menopause.

AMH may sometimes be ordered for a woman who will be undergoing assisted reproduction procedures such as in vitro fertilization (IVF); the concentration of AMH present is related to her likely responsiveness to treatment. A low level of AMH reflects poor ovarian response, indicating that a decreased number of eggs would be retrieved after ovarian stimulation. For this purpose, it is typically ordered along with other hormone tests and a transvaginal ultrasound (to count the number of follicles as a reflection of the woman's egg supply).

An AMH test may be used to evaluate polycystic ovarian syndrome (PCOS). AMH may be elevated due to the increased number of follicles present.

Some ovarian cancers produce increased levels of AMH. If the hormone is initially elevated, then the test can be used as a tumor marker to help evaluate response to treatment and monitor for recurrence.

AMH test in infants
In an infant with external genitals that are not clearly male or female (ambiguous genitalia), an AMH test may be ordered along with chromosome testing, hormone testing, and sometimes imaging scans to help determine the sex of the baby.

In an infant boy born with no visible testicles, low levels of AMH may account for the ambiguity of genitalia. If the testicles have not descended but are present in the abdomen, this test may be used to help determine whether they are functioning normally by measuring the AMH level.

An AMH test may be ordered in women when evaluating ovarian function, fertility issues, especially when considering assisted reproduction procedures such as in vitro fertilization (IVF), and when a health practitioner wants to determine a woman's likelihood of entering menopause.

AMH may be ordered when a woman has signs and symptoms of polycystic ovarian syndrome (PCOS). Some of these include:

• Abnormal uterine bleeding
• Acanthosis nigricans
• Acne
• Absence of menstrual cycle (amenorrhea)
• Decreased breast size
• Enlarged ovaries
• Excess face and body hair (hirsutism) involving male hair growth patterns, such as hair on the face, sideburn area, chin, upper lip, lower abdominal midline, chest, areola, lower back, buttock, and inner thigh
• Weight gain/obesity, with fat distribution in center of the body
• Skin tags in the armpits or neck
• Thinning hair, with male pattern baldness

AMH may be ordered periodically for a woman with an AMH-producing ovarian cancer to monitor the effectiveness of treatment and to monitor for recurrence.

An AMH test may be ordered when an infant has ambiguous genitalia or when a male child's testicles have not descended properly.

Women
During a woman's childbearing years, a decreased level of AMH may indicate a low number and quality of eggs (low ovarian reserve) with diminishing fertility, resulting in minimal or less responsiveness to IVF treatment. It can also indicate that the ovaries are not functioning normally (premature ovarian failure).

A decreasing level and/or significant decline in AMH may signal the imminent onset of menopause. Negative to low levels of AMH are normal in a female during infancy and after menopause.

An increased level of AMH is often seen with PCOS but is not diagnostic of this condition. Increased AMH may also indicate an increased or even excessive responsiveness to IVF and a need to tailor the procedure accordingly.

When AMH is used as a tool to monitor an AMH-producing ovarian cancer, then a decrease in AMH indicates a response to treatment while an increase may indicate cancer recurrence.

Infants
In a male infant, absence or low levels of AMH may indicate a problem with the AMH gene located on chromosome 19 that directs AMH production and may be seen with absent or dysfunctional testicles. Lack of male hormones may result in ambiguous genitalia and may cause abnormal internal reproductive structures. Normal levels of AMH and androgens in a male infant whose testicles have not descended indicate that they are present and functional but not physically located where they are supposed to be.

Some in the medical community are advocating the use of AMH as a more routine test, for predicting the end of fertility and the onset of menopause, but there is not a consensus on this use. It is not considered a diagnostic or "stand-alone" test, but one that supports the diagnosis of one of the conditions mentioned.

Other female hormones fluctuate with a woman's monthly cycle; however, AMH is produced by growing follicles at a relatively steady rate. It is also not affected by oral contraceptives or pregnancy. 

For most women, the AMH test is not considered necessary unless they are having fertility issues. Most women will not need to have this test performed.