Comparative Analysis of Letrozole vs. Clomiphene Citrate in Women with PCOS Undergoing Ovulation Induction

Background: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder leading to anovulatory infertility. Both Clomiphene Citrate and Letrozole are widely used for ovulation induction, but their relative effectiveness remains a subject of debate. Methods: A prospective comparative study was conducted at Department of Gynaecology and obstetrics Dr Ziauddin university Karachi from February 2023 to February 2024. A total of 71 women with PCOS were enrolled and randomly assigned to two groups: Group A (n=36) received Letrozole, while Group B (n=35) received Clomiphene Citrate. Patients were monitored with transvaginal ultrasonography for follicular growth, endometrial thickness, and ovulation. Outcomes assessed included ovulation rate, endometrial response, biochemical pregnancy, clinical pregnancy, live birth, and adverse effects. Data were analyzed using SPSS version 26, with p<0.05 considered significant. Results: Baseline demographic and hormonal profiles were similar across groups. Women treated with Letrozole developed a thicker endometrium than those receiving Clomiphene (8.7 ± 1.2 mm versus 7.3 ± 1.4 mm, p=0.001). Clomiphene induced a higher mean number of mature follicles (2.4 ± 0.8 vs. 1.8 ± 0.6, p=0.004). Ovulation and pregnancy rates were higher with Letrozole, though not statistically significant. Adverse effects such as ovarian cyst formation and hot flushes were more common in the Clomiphene group. Conclusion: Letrozole demonstrated superior endometrial development, comparable follicular response, and a trend toward better pregnancy outcomes with fewer adverse ‘effects compared to Clomiphene Citrate’. These findings support the use of Letrozole as a preferred first-line agent for ovulation induction in women with PCOS.