Efficacy of letrozole in ovulation induction compared to that of clomiphene citrate in patients with polycystic ovarian syndrome.

OBJECTIVE

To compare the efficacy of letrozole with clomiphene citrate for ovulation induction in patients with polycystic ovarian syndrome (PCOS).

STUDY DESIGN

In this clinical trial, 107 infertile patients with PCOS received either 100 mg clomiphene citrate (n = 57) or 5 mg letrozole (n = 50) daily since day 3-7 of their menstrual cycle. Human chorionic gonadotropin (hCG) was administered at a dose of 10,000 IU when at least 1 mature follicle was detected. A single intrauterine insemination was performed 34 hours later. Then the size, number and growth rate of follicles, ovulation rate, endometrial thickness and pregnancy rate were measured in both groups.

RESULTS

The number and the size of mature follicles were similar between the 2 groups. The pregnancy rate in letrozole group was higher than that in the clomiphene group (20% vs. 14%), but the difference was not significant (p = 0.286). In letrozole group, 86% of patients developed mature follicles, all showing ovulation, whereas 72% of patients in clomiphene citrate group developed mature follicles (p = 0.07).

CONCLUSION

Letrozole might be an acceptable alternative to clomiphene citrate to induce ovulation and pregnancy in PCOS patients.