The immunomodulatory role of seminal plasma in endometrial receptivity and embryo implantation.

Successful implantation and pregnancy rely on complex interactions between the embryo and the maternal reproductive tract. Seminal plasma components, including proteins, cytokines, and growth factors, are pivotal in enhancing endometrial receptivity and inducing maternal immune tolerance to the developing conceptus. Exposure to seminal plasma facilitates pathogen clearance, supports embryo development, and modulates immune responses by altering the endometrial transcriptome and promoting regulatory T cell (Treg) expansion. Proteomic studies have identified seminal plasma factors involved in these processes. Changes in the immunomodulatory components of seminal plasma can diminish its positive effects on the endometrium, potentially resulting in reduced fertility and increased risk of adverse pregnancy outcomes. This review explores how seminal plasma influences maternal immune responses and highlights the clinical implications, particularly its potential to improve outcomes in assisted reproductive technologies (ART) like in vitro fertilization (IVF). Understanding the molecular dialogue between seminal plasma and the endometrium may lead to new strategies for enhancing fertility and promoting healthy pregnancy.