Endometrial Response in Polycystic Ovarian Syndrome Treated With Letrozole Alone or With Added Estradiol Valerate

Polycystic Ovary Syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age, characterized by chronic anovulation, hyperandrogenism, and polycystic ovarian morphology. Letrozole, an aromatase inhibitor, has emerged as a first-line ovulation induction agent due to its superior ovulation and pregnancy rates compared to clomiphene citrate. However, one of the drawbacks of aromatase inhibitors is suboptimal endometrial development, which may adversely affect implantation and pregnancy outcomes. Estradiol valerate, a synthetic estrogen, can be co-administered with letrozole to improve endometrial receptivity by enhancing endometrial thickness, vascularity, and pattern. Limited data exist on whether adding estradiol to letrozole truly improves the endometrial response and clinical pregnancy rates in women with PCOS. This study aims to evaluate the effect of letrozole alone versus letrozole with estradiol valerate on endometrial development in these patients.