Comparison of Effects Letrozole and Clomiphene Citrate for Ovulation Induction in Women with Polycystic Ovary Syndrome

This study was conducted to compare the effects of letrozole (5mg) and clomiphene citrate (100 mg) in treatment of infertility in patients with polycystic ovary syndrome. This clinical trial carried out on total 100 infertile women with polycystic ovary syndrome refered to Asali hospital and private clinic in 2008 and were randomized into two group of 50 that treated with 5 mg letrozole or 100 mg clomliphen citrate from day 3 to 7 of menstrual cycle. Transvaginal ultrasound usually was performed on day 12-16 of the cycle, and more often as needed to monitor the number and mean size of developing follicles in each ovary, and the endometrial thickness. Data were analyzed by t-test and chi-square test using SPSS version 15. P-value less than 0.05 defined asstatistically significant. The means of ages, body mass index, and duration of infertility in both groups were similar. The total numbers of follicles were significantly higher in the clomiphene citrate group compared to letrozole group (2.32 1.58 vs. 1.30 0.50). Endometrial thickness was greater in the letrozole group compared to clomiphene citrate group (9.71 1.27 mm vs. 6.08 3.06 mm). The duration of stimulation was similar in two groups. Ovulation occurred in 44 (88%) of 50 patients in the letrozole group and clomiphene citrate group that was not significantly different. Letrozole and clomiphene citrate usage resulted in similar pregnancy rates. The results of this study showed that Letrozole could be used as a good alternative for clomiphene citrate for treatment of infertile women with polycystic ovary syndrome.