Anti-Müllerian hormone

AMH & AMHR2

Anti-Müllerian hormone (AMH), also known as Müllerian-inhibiting substance (MIS), is a glycoprotein hormone structurally related to inhibin and activin from the transforming growth factor beta superfamily, which has significant roles in the regulation of reproductive physiology. AMH is secreted by Sertoli cells in males and by granulosa cells in females. The primary function of AMH in males is to inhibit the development of the Müllerian ducts into the uterus and fallopian tubes during fetal development. In females, AMH is involved in the regulation of folliculogenesis, and its levels are often used as a marker of ovarian reserve.

Function

In Males

In male fetuses, AMH is produced by Sertoli cells soon after testicular differentiation. The secretion of AMH is crucial for the regression of the Müllerian ducts, which, in the absence of AMH, would develop into the female reproductive tract, including the fallopian tubes, uterus, and the upper part of the vagina. The presence of AMH ensures the proper development of male reproductive structures, such as the epididymis, vas deferens, and seminal vesicles.

In Females

In females, AMH is produced by the granulosa cells of the ovaries starting from a woman's fetal life, peaks during the early reproductive years, and declines with age until it becomes undetectable around the time of menopause. The hormone plays a key role in the formation of primary follicles by inhibiting the excessive recruitment of primordial follicles into the pool of growing follicles. This action is critical for preserving the ovarian reserve. Additionally, AMH levels in adult women are used as an indicator of their remaining egg supply, or ovarian reserve, and can be measured through blood tests to assess fertility.

Clinical Significance

AMH levels are used in the assessment of various conditions related to reproductive health. In women, low AMH levels can indicate diminished ovarian reserve, which can be a concern for those trying to conceive, as it may signal a reduced number of viable eggs. Conversely, high AMH levels are often seen in conditions like Polycystic Ovary Syndrome (PCOS), where there is an overproduction of follicles. In men, abnormal levels of AMH can indicate issues with testicular function, although the clinical applications in males are less well-defined compared to females.

Measurement

The measurement of AMH levels is performed through a blood test. This test can be done at any time during the menstrual cycle, as AMH levels are stable throughout the cycle. It is a useful tool in assessing ovarian function and can aid in the diagnosis of conditions like PCOS, premature ovarian failure, and in the evaluation of ovarian response in assisted reproductive technologies (ART).

Use in Assisted Reproductive Technologies

AMH levels are an important parameter in the management of fertility treatments, such as in vitro fertilization (IVF). They help predict how the ovaries will respond to fertility drugs. Women with very high or very low AMH levels may require tailored approaches in their fertility treatment to optimize outcomes.

Conclusion

Anti-Müllerian hormone plays a critical role in the development and function of the reproductive system in both males and females. Its measurement is a valuable tool in assessing reproductive health and guiding treatment in conditions related to fertility and ovarian function.