Patients with Polycystic Ovary Syndrome Have Altered Blastocyst Endometrium Crosstalk before Embryo Implantation

Background: Embryo implantation is defined as the process by which blastocyst attaches to the endometrium and invades to endometrial stroma cells to form the placenta. Successful embryo implantation requires exchange of mediators between endometrium and blastocyst in the form of cross talk which alter the microenvironment of the oviduct and uterus and underly the homing of blastocyst. These factors mainly include interleukins, immunosuppressive and growth factors which facilitate implantation by increase the endometrial expression of integrins, leukaemia inhibitory factor, and Polycystic ovary syndrome (PCOS) is the most common endocrine disorder and major cause of anovulatory infertility. The reduced oocyte/embryo quality and decreased implantation rate has been reported as its common complications. Herein we aimed to provide a detailed discussion regarding endometrium-blastocyst cross talk in patients with PCOS to clarify the exact etiology of their low embryo implantation rate. Methods: In the present article, the published studies in PubMed, ScienceDirect, Scopus and Google Scholar gateway and databases were assessed using the keywords: Polycystic Ovary Syndrome, Embryo Implantation, Endometrium, Blastocyst and Cytokine from January 2000 to February 2022. Results: It was found that patients with PCOS have altered profile of embryo and endometrium secretome. It led to disrupted endometrium-embryo crosstalk. Conclusion: It seems that the disrupted endometrium-embryo crosstalk in PCOS patients may be a main cause of low implantation rate among these patients. Keywords * Polycystic ovary syndrome * Embryo implantation * Endometrium * Blastocyst * Cytokine