A historical perspective of aromatase inhibitors for ovulation induction

The concept of using aromatase inhibitors in place of clomiphene citrate (CC) for ovulation induction was introduced >10 years ago; a brief history of its development is presented. Its worldwide usage for ovulation induction, including as an adjunct for intrauterine insemination and in vitro fertilization has occurred despite the absence of definitive data of superiority to CC. The results of two ongoing potentially definitive multicenter trials of efficacy and safety of letrozole compared with CC are eagerly awaited.