Letrozole is superior to clomiphene citrate in ovulation induction in patients with polycystic ovary syndrome

Objective: This study was aimed to compare the clinical outcomes of ovulation induction (OI) by timed intercourse with letrozole (LTZ) and clomiphene citrate (CC). Methods: Three hundred and twenty-three patients with polycystic ovary syndrome (PCOS) who underwent OI with LTZ or CC between February 2017 and November 2018 were included in this retrospective study. The patients were divided into two groups as the CC group (n=148) and the LTZ group (n=175). Endometrial thickness, follicular development, ovulation, clinical pregnancy, abortion, and live birth rates of the groups were analyzed. Results: The mean endometrium thickness of the CC group was 7.1 +/- 1.7 mm, and the LTZ group was 8.6 +/- 1.8 mm (p<0.001). The ovulation rate per cycle was higher in the LTZ group (93.1%) in comparison with the CC group (83.8%) (p=0.013). Clinical pregnancy rates were 52% in the LTZ group, and 41.2% in the CC group (p=0.047). LTZ with 44% of live birth rate was superior to CC with a 33% live birth rate (p=0.029). Conclusions: LTZ is an effective OI agent in PCOS patients. LTZ is superior to CC in terms of pregnancy rates and live birth rates. As a result, we recommend that LTZ should be the first-line treatment agent in patients with PCOS.