Treatment of WHO 2: Aromatase inhibitors

Worldwide, approximately 49 million couples have difficulty conceiving, of which about 20 million couples have primary infertility, and 29 million couples have secondary infertility (1). The estimated proportion of patients having an ovulatory disorder out of this population is 15%, most of them classified as WHO class 2 anovulation (PCOS prototype). A simple, safe method of ovulation induction is important because there are millions of women with anovulatory infertility around the world, many without access to ultrasound monitoring or even access to an infertility specialist. An inexpensive, oral agent for ovulation induction that has few side effects and that requires very little if any monitoring to prevent multiple pregnancies is urgently needed. We believe that the use of aromatase inhibitors fulfills these criteria. In this chapter, we describe the use of aromatase inhibitors for ovulation induction in the subset of patients with WHO 2 ovulatory problems.