COMPARATIVE ANALYSIS OF CONVENTIONAL AND EXTENDED LETROZOLE REGIMENS FOR OVULATION INDUCTION IN PCOS PATIENTS UNDERGOING INTRAUTERINE INSEMINATION (IUI)

Abstract

Background: Polycystic Ovary Syndrome (PCOS) is a leading cause of infertility, often requiring ovulation induction for conception. Letrozole, an aromatase inhibitor, has emerged as the preferred pharmacological treatment. However, the optimal dosing regimen remains debated. This study compares the efficacy of the Conventional Letrozole regimen (5 mg for 5 days) and the Extended Letrozole regimen (2.5 mg for 10 days) in PCOS patients undergoing intrauterine insemination (IUI) cycles.

Methods: This retrospective cohort study included PCOS patients undergoing ovulation induction with either Conventional or Extended Letrozole regimens. The primary outcome was total gonadotropin (HMG) usage per cycle. Secondary outcomes included follicular response, endometrial thickness, ovulation rates, incidence of hyper-response cases, and pregnancy outcomes. Statistical analyses were conducted to compare the treatment effects.

Results: A total of 29 patients (31 cycles in the Conventional Letrozole group and 58 cycles in the Extended Letrozole group) were analyzed. The Extended Letrozole group required significantly lower total gonadotropin usage (p = 0.0388), making it a more cost-effective alternative. Mean dominant follicle size was slightly larger in the Extended Letrozole group (17.6 mm vs. 16.6 mm, p = 0.08), though not statistically significant. Endometrial thickness was comparable between both groups (7.63 mm vs. 7.32 mm, p = 0.22), suggesting that prolonged Letrozole administration does not negatively impact implantation potential. The incidence of hyper-response cases was lower in the Extended Letrozole group, indicating improved cycle control.

Conclusion: The Extended Letrozole regimen demonstrated significant advantages over the Conventional Letrozole regimen, including reduced gonadotropin usage, improved cycle control, and comparable endometrial receptivity. Trend toward improved ovulatory response suggests Extended Letrozole may be a valuable alternative for ovulation induction in PCOS patients. Future large-scale studies are warranted to further evaluate its impact on live birth rates and long-term reproductive outcomes.