Fig. 1.

The pathophysiology of PCOS. Several theories have been proposed to explain the etiology of PCOS. Abnormal GnRH pulsation leads to an increase in the pulse frequency and amplitude of LH release and a relatively low release of FSH. This causes excessive androgen production, metabolic disorders, and other related performances. IR with hyperinsulinemia further increases ovarian androgen production directly and indirectly by inhibiting the production of SHBG by the liver. PCOS, polycystic ovary syndrome; GnRH, gonadotropin releasing hormone; LH, luteinizing hormone; FSH, follicle stimulating hormone