Evaluation and treatment of anovulatory and unexplained infertility.

Anovulatory disorders are a primary cause of female infertility. Polycystic ovarian syndrome is the major cause of anovulation and is generally associated with obesity. Lifestyle changes to encourage weight loss are the initial therapy for overweight and obese patients, followed by clomiphene citrate for ovulation induction. For those patients who fail to ovulate on clomiphene citrate, alternatives, such as letrozole; gonadotropins; and complimentary agents to enhance clomiphene citrate, such as metformin and glucocorticoids, are reviewed. Women with unexplained infertility (no identifiable cause of infertility on a routine evaluation) may benefit from ovulation induction with clomiphene citrate, letrozole, or gonadotropins.