A Comparison Between the Effects of Letrozole in Combination with Clomiphene and Letrozole Alone on Ovulation and Pregnancy in Infertile Patients with Polycystic Ovarian Syndrome: A Clinical Trial Study

Background and

Infertility is defined as the inability to conceive after 12 months of regular coitus. Anovulatory processes are the most common cause of infertility in women. The aim of this study was to compare the efficacy of combination treatment of clomiphene citrate (CC) and letrozole versus letrozole alone for ovulation induction and pregnancy rate in infertile women with polycystic ovarian syndrome (PCOS).

This is a single-blind, controlled trial study. A total of 102 infertile PCOS women were randomly divided into two groups. Group one (n=51) received 100 mg CC plus 5 mg letrozole daily on cycle days 3-7 for a single treatment cycle and group two (n=51) received 5 mg letrozole daily on cycle days 3-7 for a single treatment cycle. When at least one follicle reached a diameter of 18-19 mm, the patients received human gonadotropin hormone (5000 U-IV injection). The couples had regular intercourse, 2-3 times a week, as they had been instructed.

The number of follicles with a diameter of 14 mm was significantly higher in women who received the combination treatment of letrozole and clomiphene compared to the ones who received letrozole treatment (P=0.04). There were no statisticaly significant differences in the number of 18 mm follicles (P=0.07), mean endometrial thickening (P=0.37), clinical pregnancy rate (P=0.99), ongoing pregnancy rate (P=0.59), multiple pregnancy rate (P=0.99), and live birth (P= 0.99) between the two groups.

According to our study, the combination treatment of letrozole and CC is more effective than letrozole and can be used as the first-line therapy for infertility in women with PCOS. Moreover, the cost and risk of this treatment may be lower than other induction ovulation treatments.