Endometriyal Reseptivitenin İmplantasyondaki Rolü

AbstractThe Role of Endometrial Receptivity in Implantation Blastocyst implantation is a dynamic process. This process involves embryo apposition and attachment to the prepared endometrial epithelium, and invasion into the endometrial stroma. Successful implantation is the result of reciprocal interactions between the blastocyst and receptive endometrium. The endometrium undergoes precisely defined morphological changes until receptive endometrium is developed. Endometrial receptivity represents a crucial limit for the success of in vitro fertilization and embryo transfer treatments. In other words a lack of synchrony between the embryo development and endometrial maturation results in an implantation failure. Blastocyst may implant only in the receptive phase, which is characterized by unique morphological and molecular changes of the endometrium. During implantation, the apical membranes of the epithelial cells lining the uterine cavity lose their microvilli and develop large and smooth membrane projections. These projections on the endometrial surface have been suggested as ultrastructural markers of the implantation window, which are known as pinopodes. Reduced implantation rates in IVF cycles could result from impaired or premature endometrial maturation, which could be accompanied by alterations in pinopode expression. Furthermore, maternal endometrial cells are regulated directly by ovarian steroids and indirectly by various growth factors and cytokines. Endometrial differentiation to support blastocyst implantation is coordinated by progesterone and oestrogen. Nevertheless, the molecular mechanisms that render the endometrium receptive to blastocyst implantation are not fully understood. Further research in this field may offer new therapeutic opportunities.