ANTIMÜLLERIAN HORMONE (AMH) IN MEN: A KEY MARKER IN MALE FERTILITY

Introduction

Antimüllerian hormone (AMH) is a glycoprotein hormone primarily associated with female fertility assessment. However, its role in male reproductive health is equally important but often overlooked. In men, AMH is produced by Sertoli cells in the testes and plays a crucial role in testicular development, function, and fertility. This article explores the significance of AMH in male fertility, its role in adolescent males, and when AMH testing may be clinically useful.

What Is Antimüllerian Hormone (AMH)?

AMH is a member of the transforming growth factor-beta (TGF-β) superfamily, which regulates reproductive organ differentiation and development. In males, AMH production begins early in fetal life, preventing the development of the Müllerian ducts, which would otherwise give rise to female reproductive structures. AMH continues to be produced in significant quantities throughout childhood and adolescence before declining in adulthood.

AMH Production and Regulation in Men

• Fetal Life: AMH is secreted by Sertoli cells in the developing testes and inhibits the formation of Müllerian structures, ensuring normal male reproductive tract differentiation.

• Childhood and Adolescence: AMH remains elevated until puberty when its levels start to decline due to the increasing influence of follicle-stimulating hormone (FSH) and testosterone.

• Adulthood: AMH levels in adult men are significantly lower than in childhood and are primarily used as a marker of Sertoli cell function and testicular health.

Significance of AMH in Male Fertility

While AMH is widely used in assessing ovarian reserve in women, its role in male fertility assessment is still being explored. AMH serves as a biomarker of Sertoli cell function and testicular reserve, providing insight into spermatogenesis and overall testicular function.

1. AMH as a Marker of Sertoli Cell Function

Sertoli cells are crucial for supporting spermatogenesis, and AMH levels correlate with their activity. Abnormal AMH levels may indicate underlying testicular dysfunction or Sertoli cell pathology, impacting sperm production.

• Low AMH levels may suggest primary testicular failure, impaired spermatogenesis, or a history of cryptorchidism.

• High AMH levels in adult men can indicate Sertoli cell immaturity or dysfunction, often seen in disorders like persistent Müllerian duct syndrome (PMDS) or certain cases of infertility.

2. AMH and Spermatogenesis

AMH levels are indirectly related to spermatogenesis. Studies have shown that men with non-obstructive azoospermia (NOA) tend to have significantly lower AMH levels, suggesting that AMH could serve as a predictive marker for spermatogenic failure.

• A study by Pallotti et al. (2019) found that men with NOA had significantly lower AMH levels than those with obstructive azoospermia (OA), making AMH a useful biomarker in distinguishing between these conditions.

3. AMH and Hypogonadism

Hypogonadotropic hypogonadism (HH) is a condition characterized by low gonadotropin (LH/FSH) levels leading to impaired testosterone production and spermatogenesis. Men with HH often have higher-than-normal AMH levels due to the lack of FSH-mediated Sertoli cell maturation.

4. AMH and Testicular Function in Adolescents

In adolescent males, AMH plays a key role in pubertal development and serves as a marker of testicular function.

• Delayed Puberty: Adolescents with delayed puberty or hypogonadism may exhibit persistently high AMH levels due to immature Sertoli cells.

• Precocious Puberty: A rapid decline in AMH before the expected age can indicate premature testicular maturation and may require endocrinological evaluation.

When Should We Test AMH in Men?

Although AMH testing is not routinely included in male fertility workups, it can be useful in specific clinical scenarios.

1. Evaluation of Infertility

AMH levels may help differentiate between obstructive and non-obstructive causes of azoospermia and provide insight into spermatogenic potential.

• Low AMH + High FSH: Suggests testicular failure or impaired spermatogenesis (e.g., non-obstructive azoospermia).

• Normal AMH + Normal FSH: Suggests possible obstructive azoospermia (e.g., congenital bilateral absence of the vas deferens).

2. Assessment of Cryptorchidism or Disorders of Sexual Development (DSD)

• In boys with bilateral undescended testes, AMH measurement can help distinguish between anorchia (absent testes) and cryptorchidism (undescended but functional testes).

• In patients with DSD, AMH levels may assist in determining the presence and function of testicular tissue.

3. Monitoring Hypogonadism and Pubertal Disorders

• Delayed puberty with high AMH suggests hypogonadotropic hypogonadism.

• Precocious puberty with an early decline in AMH may indicate premature testicular maturation.

4. Evaluation of Persistent Müllerian Duct Syndrome (PMDS)

PMDS is a rare disorder where AMH fails to suppress Müllerian structures, leading to the presence of uterine remnants in otherwise phenotypic males. Elevated AMH levels with a history of cryptorchidism may indicate PMDS.

5. Testicular Tumor Marker

Although not commonly used, AMH can be an adjunct marker for certain testicular tumors, particularly those of Sertoli cell origin.

Interpreting AMH Test Results in Men

Limitations of AMH Testing in Men

While AMH provides valuable insights into testicular function, it has limitations:

• AMH is not a direct marker of spermatogenesis; it only reflects Sertoli cell activity.

• Reference ranges for male AMH levels are not well standardized.

• AMH should always be interpreted alongside other markers such as FSH, LH, testosterone, inhibin B, and semen analysis.

Conclusion

AMH is a crucial hormone in male reproductive physiology, serving as a biomarker of Sertoli cell function, testicular reserve, and potential spermatogenic capacity. While not routinely included in male fertility assessments, AMH testing can be useful in evaluating azoospermia, cryptorchidism, delayed puberty, hypogonadism, and disorders of sexual development. Future research may further elucidate its role in male fertility diagnostics and treatment.

References

1. Pallotti, F., et al. (2019). "Antimüllerian hormone as a predictive marker for spermatogenic failure in non-obstructive azoospermia." Andrology.

2. Grinspon, R. P., & Rey, R. A. (2010). "Antimüllerian hormone and Sertoli cell function in paediatric male hypogonadism." Hormone Research in Paediatrics.

3. Carlsen, E., et al. (2020). "Clinical significance of AMH in male reproductive health: A review." Journal of Clinical Endocrinology & Metabolism.

Reach out to me with questions: bgilbert@nycryo.com