A randomized trial of ovulation induction with two different doses of Letrozole in women with PCOS

Abstract

Objective: To compare the effects of either a 5 or 7.5 mg daily dose of Letrozole in PCOS women undergoing ovulation induction and timed intercourse.

Design: Prospective randomized trial.

Setting: Academic infertility care center.

Patients: Sixty-seven PCOS patients with infertility.

Interventions: Patients were randomly divided into two groups and treated with either 5 mg/day (30 patients, group 1) or 7.5 mg/day (37 patients, group 2) Letrozole for 5 days starting from day 3 of the menstrual cycle. When the leading follicle reached 18 mm in diameter, ovulation was triggered by an injection of HCG and timed intercourse was advised thereafter.

Main outcome measures: The primary outcome measures were the number of follicles and days to reach mature follicle and the secondary endpoints were endometrial thickness, day 7 testosterone level, ovulation and pregnancy rates.

Results: The mean age, BMI, duration of infertility and basal hormone levels in both groups were similar. There was no significant difference in the endometrial thickness (7.87 ± 1.67 vs 7.16 ± 2.04), the number of intermediate (0.83 ± 0.75 vs 0.62 ± 0.76) and mature follicles (1.13 ± 1.11 vs 1.22 ± 1.03) on days 12-14 between group 1 and 2, respectively. The days to reach mature follicle were similar in both groups (12.8 ± 1.36 vs 12.6 ± 1.22). Also there was no significant difference in the day 7 testosterone level and day 21 progesterone level between the two. Ovulation occurred in 90 and 89.2% of patients in group 1 and 2, respectively without a statistically significant difference. The pregnancy rate per first ovulatory cycle was 25.8% in group 1 and 21.2% in group 2 without significant difference. No OHSS was observed in either group.

Conclusion(s): The results of this study did not show any advantage to the use of 7.5 mg/day over 5 mg/day dose of Letrozole as the first line treatment for induction of ovulation in women with PCOS.