Polycystic ovary syndrome: a focus on anti-Müllerian hormone levels

Anti-Müllerian hormone (AMH) is a dimeric glycoprotein exclusively produced by the granulosa cells and reflects the size of the growing follicular pool. Serum AMH levels seem to correlate with the development of preantral and small-antral follicles during reproductive life. It has been established that AMH levels are two- to threefold higher in adult women with polycystic ovary syndrome (PCOS) compared with healthy women. This may be related to an increased number of growing follicles that secrete AMH or to an increased per granulosa cell production. Therefore, the understanding of its regulation is important to advance the comprehension of PCOS pathophysiology. Apparently, androgens may play an important role in this regard. Recently, our group documented higher serum levels of AMH in daughters of women with PCOS compared with control girls during three stages of sexual development, early infancy, childhood and peripuberty, suggesting the presence of an increased growing follicular pool in these girls that is established early in development and precedes the onset of clinical hyperandrogenism. In addition, clinical and experimental studies suggest that androgens could also have a role in determining an increased follicular mass during prenatal life, which, during postnatal life, may perpetuate hyperandrogenism. Currently, AMH determination is being progressively used in clinical practice as a marker of ovarian function. In the future, it may become a useful tool to assess ovarian aging and reserve, to diagnose PCOS and to evaluate treatment success.