Anti Mullerian Hormone

Anti Mullerian Hormone or AMH is produced primarily by the testicles in males and the ovaries in females. AMH levels in blood determine and regulate a number of activities of the human reproductive system.

In the first few weeks of foetal development during pregnancy, the foetus has both the primordial male and female reproductive systems and can develop either as male or female. In genetic males, high amounts of AMH are secreted by the testicles, suppressing the formation and development of the female reproductive organs from Mullerian ducts (primordial female reproductive system), and encouraging the development of other male sex organs, which results in the development of a male child. Low or no AMH secreted in the genetically female foetus causes the formation and development of female reproductive organs from the Mullerian duct and a female child is developed. Abnormalities in AMH levels in the foetus may cause the formation of ambiguous genitalia.

After birth, AMH levels remain high in males till puberty, after which they fall slowly and tapers off. AMH levels in females remain low after birth till puberty. During puberty, AMH is secreted by the ovaries resulting in sharp increase in its levels which slowly fall throughout the female reproductive period and become very low to undetectable after menopause. AMH maintains a balance of the two important female reproductive hormones: Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH), which regulate maturation and release of eggs from the ovaries along with other hormones. Hence, AMH levels during the female reproductive period serve as an indication of the ovarian reserve (number of remaining eggs that can mature fully and be released for reproduction), and hence fertility. It is also an indicator of the onset of menopause, especially in older women.

AMH can also be produced by ovarian cysts formed during PCOS, as well as by some types of ovarian tumors.