Anti-Müllerian Hormone (serum, plasma)

1.4. Function(s) of analyte AMH, a dimeric glycoprotein, is a member of the transforming growth factor β family of growth and differentiation factors. During normal male foetal sexual development, testicular production of AMH, secreted by Sertoli cells from the 7th week of gestation, plays a vital role in male sexual differentiation. It is responsible for the involution/regression of the female Müllerian duct while testosterone from Leydig cells stimulates differentiation of the male Wolffian ducts, the urogenital sinus and the external genitalia. In females, AMH is released from granulosa cells of preantral and small antral follicles but is not present until the 36th week of gestation, after formation of the Müllerian duct. AMH concentrations in boys are very high until puberty when they drop significantly following the increased testosterone production that downregulates AMH, probably via activation of the Sertoli cell androgen receptor. However, post pubertal concentrations of AMH in males remain significantly higher in general that those seen in adult females, although there is a significant overlap in values. Female AMH concentrations are low at birth, rise gradually and stabilise during the first few years of life and then remain relatively constant during the pubertal transition. After the mid-twenties, concentrations gradually decline, becoming undetectable after the menopause. The primary function of AMH in females is to preserve the follicular pool, mainly by resisting follicular recruitment induced by FSH.