Figure 1.

The roles of AMH (Anti-Müllerian Hormone) in PCOS (Polycystic Ovary Syndrome). In the physiological cycle, during the FSH (Follicle Stimulating Hormone) independent phase, AMH expression is lower in activated primordial follicles and highest in preantral and small antral follicles. In the FSH dependent phase, the expression of AMH is blocked. However, lower expression of AMH is observed in the preovulatory follicle. Therefore, the absence of AMH leads to an increased Estradiol level in antral and preovulatory follicles. In PCOS, the expression of AMH increases twofold, leading to an increased number of recruited follicles. In addition, such a high level of AMH reduces FSH expression and Estradiol synthesis, thereby blocking the selection phase and thus the formation of a preovulatory follicle.