Effect of Sildenafil Citrate on the Outcome of in vitro Fertilization after Multiple IVF Failures Attributed to Poor Endometrial Development: A Randomized Controlled Trial

Abstract

he etiology of infertility is diverse. Despite the improvement in ovarian stimulation protocols and techniques, results of in vitro fertilization (IVF) have unfortunately reached a plateau. Diverse and unexplained factors affecting implantation rates have become a major limiting factor. Therefore, more attention needs to be focused on implantation and endometrial receptivity. Good embryo quality, appropriately timed and arranged endometrial receptivity, and efficient crosstalk between the embryo and the receptive endometrium are required for successful implantation. Impairment of any one of these factors may result in implantation failure. To improve poor endometrial response, several regimens have been put forward, including treatment with estrogens and low dose aspirin. Sildenafil citrate improves the uterine artery blood flow and the endometrial thickness in women with a prior failed assisted reproductive cycle due to poor endometrial response. Sildenafil citrate can be used orally or by vaginal to improve endometrial receptivity. The aim of the study is to evaluate the efficacy of the orally administered sildenafil citrate on the endometrial thickness and pregnancy rate in infertility patients undergoing IVF.