Letrozole outperforms clomiphene citrate for ovulation induction

The use of letrozole for inducing ovulation in women with infertility and polycystic ovarian syndrome (PCOS) appears to yield improvements in ovulation, pregnancy, and live-birth rates as compared with clomiphene citrate, according to a study.

Researchers performed a systematic review and meta-analysis of studies on the effect of letrozole vs clomiphene citrate on ovulation induction outcomes in women with infertility and PCOS. They searched multiple online databases for relevant studies.

Two reviewers examined the studies and independently retrieved, filtered, and extracted data using two software programs. Data were collected and organized in accordance with the 2020 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement.

A total of 29 randomized controlled trials were included in the meta-analysis. These trials involved 3,952 women and 7,633 ovulation induction cycles. Of the trials, 22 provided data for the ovulation rate, 28 for the clinical pregnancy rate, and eight for live-birth rate.

Pooled data showed that compared with clomiphene citrate, letrozole treatment was associated with significantly better ovulation rate (risk ratio [RR], 1.14, 95 percent confidence interval [CI], 1.06–1.21; p<0.001), clinical pregnancy rate (RR, 1.48, 95 percent CI, 1.34–1.63; p<0.001), and live-birth rate (RR, 1.49, 95 percent CI, 1.27–1.74; p<0.001).

The findings indicate that letrozole may be a better option than clomiphene citrate as an ovulation induction drug in women with infertility and PCOS, although the quality of the evidence is mixed.