Abstract: In recent years, an increasing number of high-quality embryos are obtained accompanied by the development of assisted reproductive technology. However, the embryo implantation rate still remains unsatisfactory in the clinic. Therefore, endometrial receptivity becomes a key step for the successful embryo implantation. Leptin, a common adipokine, activates downstream signaling pathways and synthesizes transcription factors by binding to leptin receptors on target cell membranes, then interacts with DNA elements in the promoter region of specific genes to initiate transcription, plays an important biological role. It has been widely proven that leptin is significantly influencial in human reproductive function. In particular, leptin affects the expression of reproductive regulatory factors associated with embryo implantation, maternal endocrine and metabolic status, and endometrial microenvironment. Furthermore, more recent researches documented that both leptin and leptin receptor were high expressions on the endometrium in both human and rodents. Thus, it is considerable that leptin has taken an effect on the endometrial receptivity directly or indirectly. This review summarizes the research advances in relationship between leptin and endometrial receptivity in order to provide a new biomarker for the evaluation of endometrial receptivity clinically.

Key words: Leptin, Receptors, leptin, Cytokines, Endometrium, Endometrial receptivity