Assessment of Endometrial and Sub-endometrial Vascularity Before and After PRP Infusion in Frozen Embryo Transfer Cycles

A good quality embryo and receptive endometrium are important aspects in achieving optimal outcomes in assisted reproductive treatment (ART). Endometrial thickness is an important marker of uterine receptivity. A thin endometrium defined by an endometrial thickness ≤7mm was reported as a poor factor associated with significantly lower implantation and pregnancy rates as well as a higher risk of miscarriage. Nowadays, platelet-rich plasma (PRP) intrauterine infusion is a promising approach for the treatment of refractory thin endometrium in patients undergoing frozen-thawed embryo transfer. This is based on its ability to stimulate proliferation and angiogenesis with a large number of growth factors and cytokines i.e. the endometrium becomes thicker, with higher vascularity. PRP is easily prepared from an autologous blood sample that eliminates the risk of immunological reactions and transmission infections at low cost. Endometrial blood flow is another important marker reflective of uterine receptivity. Although publications are increasing concerning the efficacy of PRP intrauterine infusion on endometrial expansion and proliferation in frozen-thawed embryo transfer cycles, yet its angiogenetic effects have not been evaluated so far in either thin endometrium or normal endometrium thickness. Our study aims to evaluate endometrial and sub-endometrial vasculature patterns before and after PRP infusion in frozen-thawed embryo transfer cycles with normal endometrium thickness.