Polycystic ovary syndrome. Polycystic ovary syndrome is a disorder of unknown cause characterized by anovulation, hyperandrogenism, and gonadotropin secretory abnormalities producing oligo-ovulation or anovulation. Hyperinsulinemia and insulin resistance are important features of this syndrome. Because other causes of androgen excess may produce similar clinical and biochemical findings, PCO remains a diagnosis of exclusion. Treatment is directed toward relieving symptoms of hyperandrogenemia in order to stimulate ovulation, correcting obesity, and inducing regular menses to reduce the risk of endometrial cancer. 