Ovulation induction with letrozole in women with polycystic ovary syndrome

Abstract

Study question: What is the effectiveness of first-line letrozole treatment in anovulatory women with polycystic ovary syndrome (PCOS) and what ovulation induction protocols are followed in Dutch fertility clinics? Relevance and methods: This study was done to determine the feasibility of a randomized trial comparing prolonged letrozole treatment with switching to gonadotrophins in women ovulating but not getting pregnant on first-line treatment with letrozole. We evaluated an individual participant database consisting of data from all studies that had compared letrozole to clomiphene citrate in randomized controlled trials. Furthermore, we developed a questionnaire for a national survey to assess the current protocols on ovulation induction in Dutch fertility clinics. Interpretation of results and conclusion: In women with polycystic ovary syndrome, letrozole is more effective than clomiphene citrate in terms of both ovulation rates and live birth rates among ovulating women. With about half of the ovulating women achieving live birth on first-line letrozole treatment and given the willingness of Dutch clinics to participate in a trial, we consider a randomized controlled trial comparing letrozole versus gonadotrophins as second-line treatment after ovulation on a first-line letrozole treatment in the Netherlands to be relevant and feasible.