Clomiphene ovulation induction and higher-order multiple pregnancy.

Clomiphene citrate is a widely used treatment for ovulatory dysfunction in women seeking pregnancy. The major adverse consequence of clomiphene use is the increased risk of multiple and higher-order multiple pregnancy. Mechanisms for multiple pregnancy include dosing variation, adjuvant therapies, pretreatment weight loss and a cumulative effect of multiple clomiphene cycles. It has been suggested that the risk of higher-order multiple pregnancy may be reduced with ultrasound monitoring, although there is limited evidence to support this practice.