Effect of intrauterine administration of human chorionic gonadotropin one day before fresh blastocyst transfer on clinical outcomes: a quasi-experimental study.

Introduction: embryo implantation is a crucial step for assisted reproductive technology (ART) achievement. Human chorionic gonadotropin (hCG) is one of the main regulators of the implantation process. Studies focusing on the impact of intrauterine hCG infusion at the time of embryo transfer on clinical ART outcomes have shown controversial results, mainly at blastocyst stage.