We previously hypothesized that the excess of Anti-Mullerian Hormone (AMH) at the level of ovarian selectable follicles could be involved in the follicular arrest of Polycystic Ovary Syndrome (PCOS), mainly through inhibition of FSH effect on aromatase expression.In this study, we plan to investigate whether a drop in the serum AMH level would be concomitant to the appearance of a dominant follicle induced by administration of mild amounts of exogenous FSH in women with PCOS.