Current Understanding of Anti-Müllerian Hormone

Abstract

During the last years, anti-Mullerian hormone (AMH) has been transformed into a “hot issue” of Reproductive Medicine, as it has attracted the attention of many research groups and has found considerable clinical applications. In this review, we have summarized available evidence on possible roles of AMH in women with polycystic ovary syndrome (PCOS). We have arranged the material into three sections. In the first section, we briefly present the AMH as a molecule, in the second we pay special attention on AMH involvement in PCOS pathophysiology and, in the third ­section, we discuss possible roles of AMH as a predictive factor in women with PCOS undergoing assisted reproduction technologies (ART). Serum AMH concentrations, being stable and consistent throughout the menstrual cycle, constitute a reliable marker of ovarian reserve; thus, AMH has already found a role in the clinical practice, particularly when combined with classic markers of ovarian reserve such as age, follicle-stimulating hormone (FSH), and antral follicle count (AFC). The significance of AMH in women with PCOS undergoing ART is increasing as well. On top of being a marker of ovarian reserve, AMH has been used for predicting success of ovulation induction and controlled ovarian hyperstimulation protocols, as well as avoidance of ovarian hyperstimulation syndrome (OHSS). Despite this evidence, many issues remain to be elucidated. AMH physiology is still obscure, especially its exact role in ovarian folliculogenesis, significance of serum and follicular fluid concentrations, and ­possible extraovarian actions. As far as PCOS is concerned, there is agreement that AMH concentrations are elevated in women with the syndrome as compared to normo-ovulatory women. Nevertheless, it is still not known if this difference is the result of disrupted folliculogenesis, due to increased number of small antral follicles, or the cause of it, due to AMH inhibition on folliculogenesis. Data on AMH pathophysiology in adolescent girls with PCOS are particularly scarce. The answers to these questions will broaden the spectrum of AMH clinical applications. Adjustment of overall ART strategy and individualization of protocols according to AMH concentrations seems to constitute possibilities for the near future. More distant applications could include use of AMH in hormonal contraception, given its inhibitory action on ­follicular development, or even development of AMH-antagonists in the therapeutic approach of women with PCOS.