Letrozole for Ovulation Induction in Women With Polycystic Ovary Syndrome

Importance: Polycystic ovary syndrome (PCOS) affects about 5% to 20% of women worldwide in their fertile years and often combines with infertility. Ovulation induction is often needed for those who want to get pregnant. Objective: To review the research advances of letrozole for ovulation induction in women with PCOS. Evidence Acquisition: The papers are searched in Cochrane libraries, SinoMed, PUBMED, and EMBASE till June 2024 and reviewed. Results: Letrozole, one of the third-generation of aromatase inhibitors, is increasingly recommended as a first-line agent for ovulation induction in anovulatory PCOS women due to better pregnancy and live birth rates, especially in those with clomiphene citrate (CC) resistance (CC is an earlier contacted and frequently used ovulation inducer). In this review, we focus on the usages, advantages, and disadvantages of letrozole for ovulation induction in PCOS, and show that different timing of initiation, extending treatment duration, stair-step protocol, and letrozole combined with other drugs such as FSH, ethinylestradiol and cyproterone acetate, metformin, aspirin, dexamethasone, and N-acetylcysteine. Conclusions: Letrozole is effective for inducing ovulation and achieving pregnancy in patients with PCOS, and report variations in letrozole treatment protocols. Relevance: Better understanding of letrozole for ovulation induction is important for gynecologists and women with PCOS to achieve better pregnancy and live birth rates.