In women, to assess ovarian function and menopausal status; in the evaluation of polycystic ovary syndrome (PCOS) or to evaluate the effectiveness of ovarian cancer treatment; in an infant, to evaluate the presence of external sex organs that are not clearly male or female (ambiguous genitalia) and/or function of the testicles in an infant boy
When a healthcare practitioner wants to evaluate a woman's fertility, predict onset of menopause, suspects PCOS, or wants to evaluate the cause of male characteristics in a female (virilization); sometimes prior to some assisted reproductive procedures; periodically when a woman is undergoing treatment for an AMH-producing ovarian cancer; when it is suspected that the testicles of an infant boy are absent, hidden, or not functioning properly
A blood sample drawn from a vein in your arm
Anti-Müllerian hormone (AMH) is a hormone produced by reproductive tissues, including the testicles in males and the ovaries in females. The role of AMH and the amount normally present varies depending upon sex and age. This test measures AMH in the blood.
Very early in the development of a baby boy, AMH is produced by the testicles, inhibiting the development of female reproductive organs while promoting the development of other male reproductive organs. In boys, the level of AMH remains high until puberty, when it begins to taper off.
In girls, low levels of AMH are produced, thus allowing the development of female reproductive structures. The AMH level in young girls remains low until puberty, when the ovaries begin to produce it and levels increase. AMH will then steadily decline in women over their reproductive years, becoming very low and eventually undetectable after menopause.
AMH is important for a woman during her childbearing years. At birth, a female has about one million eggs (oocytes), which then decrease naturally in number during childhood to about 500,000. Only a tiny number of these remaining eggs will go through follicle maturation – one at a time as part of a woman's monthly menstrual cycle. AMH has a balancing effect on the monthly cyclical actions of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) during the process of egg maturation and release (ovulation). The amount of AMH present is a reflection of this follicular growth.
Studies have shown that the AMH level may be useful in determining a woman's remaining egg maturation potential (ovarian reserve) and her likelihood of conceiving. AMH declines over time during childbearing years, drops significantly as menopause approaches, and typically becomes almost undetectable after menopause. Determining the AMH level may be useful in evaluating a woman's current fertility status and may predict the onset of menopause.
Elevated AMH levels have been associated with a condition affecting the ovaries known as polycystic ovary syndrome (PCOS). The excess follicles that occur in this syndrome produce abnormally large amounts of AMH.
AMH also plays a vital part in sexual differentiation in the fetus. During the first few weeks of pregnancy, a developing baby has the potential to develop either male or female reproductive organs. Production of AMH and androgens by the two testicles that are present in a baby boy inhibits development of female reproductive organs (the Müllerian ducts found in both male and female fetuses) and promotes the formation of other male reproductive organs. If a sufficient amount of AMH is not available or absent during this process, then both male and basic female organs may develop. A baby born with ambiguous genitalia may not be instantly recognized as either male or female.
AMH may be elevated in some ovarian tumors (benign or cancerous). If a tumor produces the hormone, then the AMH test can be used as a tumor marker to monitor the effectiveness of treatment and to monitor for recurrence.
How is the test used?
Anti-Müllerian hormone (AMH) is not a routinely ordered test but may be useful in specific circumstances.
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) while being evaluated for infertility. These tests are useful in evaluating ovarian function and possibly in predicting the onset of menopause. In these cases, the clinical use is however best confined to women seeking fertility rather than predicting time to 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).
AMH may be used to determine whether a woman has entered menopause.
An AMH test may be used to evaluate polycystic ovary 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.
When is it ordered?
An AMH test may be ordered in women when evaluating ovarian function and fertility issues, especially when considering assisted reproduction procedures such as in vitro fertilization (IVF). It may be ordered when a healthcare practitioner wants to determine whether a woman has entered menopause.
- Abnormal uterine bleeding
- Acanthosis nigricans
- 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.
An AMH test may be ordered when a female begins to develop male characteristics (virilization).
What does the test result mean?
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). Increased AMH may indicate an increased or even excessive responsiveness to IVF and a need to tailor the procedure accordingly.
A decreasing level and/or significant decline in AMH may signal the imminent onset of menopause or that a woman has entered 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.
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.
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.
In a female who develops male characteristics, if the AMH levels are in the male reference range, it is most likely coming from a tumor or testicular tissue and if the levels are in the female range, it is likely from the adrenal glands.
How long does it take for AMH results?
This test requires specialized equipment and must be performed in a laboratory. Your blood may need to be sent to a reference laboratory and it may take one to several days for results to be available.
Is there anything else I should know?
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 throughout the month. It is also not affected by oral contraceptives or pregnancy.