Comparison of efficacy of letrozole and clomiphene citrate in ovulation induction for women with polycystic ovarian syndrome

Background: A prospective, controlled clinical trial was performed at university hospital and comprised 98 patients (120 cycles) with PCOS. Aim(s): To compare the efficacy of letrozole and clomiphene citrate in ovulation induction for women with polycystic ovarian syndrome (PCOS). Methods: Patients were divided into three groups. Patients receiving ovulation induction for the first time randomly established to the first two groups and were treated with 100 mg/day clomiphene citrate (1st group) or 2.5 mg/day letrozole (2nd group). The 3rd group consisted of patients who failed to ovulate after CC treatment and 2.5 mg/day of letrozole was given. Main outcome measures were number of mature follicles, ovulation and pregnancy rate (PR). Results: There were no significant differences between the 1st and 2nd groups with respect to number of mature follicles (1.02 +/- 0.83 vs. 0.83 +/- 0.68), and in gruop 1 and 2 the number of mature follicles were significantly greater than group 3 (0.4 +/- 0.25). There were no significant differences between the 1st and 2nd groups with respect ovulation rate (72.5% vs. 70%), and in both groups ovulation rate were greater than group 3 (37.5%). The pregnancy rate was 20% in group 1 and 17.5% in group 2 without significant differences, while pregnancy was not detected in group 3. Conclusions: 2.5 mg/day letrozole is as effective as clomiphene citrate for ovulation induction in patients with PCOS.