At a glance
Also known as
AMH; Mullerian-inhibiting hormone; MIH; Mullerian inhibiting factor; MIF; Mullerian-inhibiting substance; MIS; 'egg timer' test
Why get tested?
In women, to evaluate ovarian function and fertility; sometimes in the evaluation of polycystic ovarian syndrome (PCOS), or to evaluate the effectiveness of ovarian cancer treatment. To evaluate the presence of nonspecific external sex organs (ambiguous genitalia) and/or function of the testicles in a male infant.
When to get tested?
When a doctor wants to evaluate a woman's fertility, predict onset of menopause, or suspects PCOS; 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 a male infant are absent or not functioning properly
A blood sample drawn from a vein in your arm
Test preparation needed?
What is being tested?
This test measures anti-Mullerian hormone (AMH) in the blood. AMH is a produced by reproductive tissues; it is produced in the testicles in males and in the ovaries in females. The role of AMH and the amount normally present varies depending upon sex and age.
Very early in the development of a male , 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 about 2 to 6 years of age, when it begins to taper off, and then it drops considerably at puberty.
Since female foetuses have no testicles, no AMH is produced at this stage and the absence of AMH allows 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 significantly. In women, AMH will then steadily decline over their reproductive years, becoming very low and then undetectable after menopause.
AMH is important for a woman during her childbearing years. At birth, a female has about 1 million eggs (oocytes), which decrease in number during childhood to about 500,000. While many of these eggs do not mature due to natural degradation, a finite number of them are rescued by the follicle-stimulating hormone (FSH) to form mature follicles. AMH has a balancing effect on the cyclical actions of FSH during the monthly process of egg maturation and release (ovulation) as influenced by the presence of luteinising hormone (LH). 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. Determining the AMH level is 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 ovarian syndrome (PCOS). The excess follicles that occur in this syndrome produce abnormally large amounts of AMH, as also may be found in certain rare types of ovarian and testicular tumours.
As stated earlier, AMH also plays a vital part in sexual differentiation in the foetus. During the first few weeks of pregnancy, a baby has the potential to develop either male or female reproductive organs. Production of AMH and by the two testicles that are present in a baby boy inhibits development of female reproductive organs (the Mullerian ducts found in both male and female foetuses) 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 recognised as either male or female.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.