RETRACTED: Clomiphene citrate or letrozole for ovulation induction in women with polycystic ovarian syndrome: a prospective randomized trial (Retracted Article)

Objective: To compare the effects of letrozole (5 mg) and clomiphene citrate (100 mg) for ovulation induction in women with polycystic ovary syndrome (PCOS). Design: Prospective randomized trial. Setting: University teaching hospital and private practice setting. Patient(s): The study comprised a total of 438 infertile women (1063 cycles) with PCOS. Intervention(s): Patients were randomized to treatment with 5 mg of letrozole daily (248 patients, 545 cycles) or 100 mg of clomiphene citrate day (220 patients, 518 cycles) for 5 days starting on day 3 of menses. Timed intercourse was advised 24 to 36 hours after hCG injection. Main Outcome Measure(S): Number of follicles, serum estradiol, serum progesterone, endometrial thickness, and pregnancy and miscarriage rates. Result(s): The mean age, parity, and duration of infertility in both groups were similar. The total number of follicles was statistically significantly greater in the clomiphene citrate group(6.8 +/- 0.3 versus 4.4 +/- 0.4). Endometrial thickness at the time of hCG administration was statistically significantly greater in the CC group (9.2 +/- 0.7 mm versus 8.1 +/- 0.2 mm). The duration to reach a dominant follicle was statistically significantly longer in the letrozole group (12.1 +/- 1.3 versus 8.8 +/- 2.9 days). Ovulation occurred in 365 out of 540 cycles (67.5%) in letrozole group and 371 out of 523 cycles (70.9%) without a statistically significant difference. Levels of serum estradiol and progesterone were statistically significantly higher in the clomiphene citrate group. The pregnancy rate per cycle was 15.1% in the letrozole group and 17.9% in the clomiphene citrate group without statistically difference between the groups. Conclusion(S): The results of this study did not show any advantage to the use of letrozole over clomiphene citrate as a first-line treatment for induction of ovulation in women with PCOS. (Fertil Steril (R) 2009;92:849-52. (C)2009 by American Society for Reproductive Medicine.)