Comparison of the effects of letrozole and clomiphene citrate for ovulation induction in infertile women with polycystic ovary syndrome

Abstract

Aim: Ovulation dysfunction is one of the most common causes of reproductive failure in infertile couples. The prevalence of this disorder in infertile women is about 30 to 40%. Polycystic ovary syndrome is a common disease that is closely related to ovulation dysfunction and 7% of women of childbearing age are afflicted with it. Ovulation induction is a way to treat infertility in PCOS which is possible through medication or surgery. This study was conducted to compare the effects of Letrozole and Clomiphene citrate for ovulation induction in women with PCOS.

Methods: This intervention is a clinical trial study carried out on 100 infertile women with polycystic ovary syndrome who were referred to gynecologist's office and Oslian hospital. The subjects were randomly divided in to two groups including 50 patients who received letrozole and Clomiphene Citrate. Abdominal ultrasound was performed on the day 14 of the menstrual cycle to monitor the number and size of developed follicles and endometrial thickness.%age of ovulation was compared between the two groups receiving medication with χ2 test and t-test was used to compare the average number and size of follicles and endometrial thickness. Twenty-three cases (46%) in group receiving clomiphene citrate had thin endometrium and thin endometrium was observed in 1 case (2%) of group receiving letrozole. Among 50 subjects who received clomiphene citrate, 10 people (20%) reported blurred vision, 9 patients (18%) headache, 6 patients (12%) nausea and 2 patients (4%) reported vomiting and one (2%) twin pregnancies was observed, but no complications were reported in group receiving letrozole.

Results: Mean age, parity, and the duration of infertility were similar in all patients. Ovulation rate was 88%; similar in both groups. The average number of follicles in the group receiving clomiphene citrate was 58/1±32/2 and in the group receiving letrezole it was 50/0±30/1. Average follicle size in both groups was almost similar. Endometrial thickness in the group receiving letrezole was 27/1±71/9 and in the group receiving clomiphene citrate it was 06/3±08/6. Pregnancy rate in both groups was almost similar.

Conclusion: This study showed that stimulation of letrozole and clomiphene citrate on ovulation and was almost the same and clomiphene citrate caused endometrial thinning more often than letrozole. Also the side effects reported by patients in the group receiving clomiphene citrate were higher, while in the group receiving letrozole no complication was reported. Based on these findings letrozole can be considered an appropriate alternative for clomiphene citrate without side effects.