Author(s): Rajat Kumar Ray, Sunita Samal

BACKGROUND Polycystic ovarian Syndrome (PCOS) is a chronic condition with manifestations that begin most commonly in adolescence with menstrual irregularity and hyperandrogenism, with a transition over time into problems including infertility and metabolic complications. It is the most common cause of anovulatory infertility & affects 12-21% of reproductive-aged women. Clomiphene Citrate (CC) has been used for ovulation induction for decades as a first line treatment. Clomiphene has drawbacks, including its overall poor efficacy, a relatively high multiple-pregnancy rate and an undesirable side-effect profile. To overcome these side effects, Aromatase inhibitors like Letrozole were proposed as new ovulation-inducing drugs. The aim of the study is to compare the efficacy of letrozole versus clomiphene citrate in ovulation induction in patients with PCOS. MATERIALS AND METHODS 166 women with PCOS were enrolled in the study. They were randomly divided into group A receiving letrozole (84 patients) & group B receiving CC (82 patients). Patients in the letrozole group were started with 2.5 mg of letrozole daily for 5 days starting on day 2 of the cycle, whereas patients in the CC group were started with 100 mg of CC daily starting day 2 of the cycle for 5 days. The primary outcome measures were presence of ultra sonographically detected pregnancy. Secondary outcomes included ovulation, endometrial thickness on day of HCG. Settings and Design- Randomised Control Trial. Statistical Analysis- Data were statistically analysed using by Student's t test. Proportions were analysed using the chi-square test. Results were expressed as mean and standard error of the mean. P<0.05 was considered as a statistically significant difference. RESULTS There were no statistically significant differences between the two groups in age, duration of infertility, body mass index (BMI). The number of mature follicles was significantly lower in women who received letrozole, but the endometrial thickness, ovulation rates & pregnancy rates were significantly higher in the letrozole group than in the CC group. Pregnancy rates were 21% in letrozole group vs 9% in clomiphene group. CONCLUSION Letrozole is more effective than clomiphene citrate as a first-line drug for inducing ovulation in women with PCOS.