Keywords: انتقال خون اندوتلیال به خونریزی; Placenta; Hematopoiesis; Vasculogenesis; Angiogenesis; Hematopoietic emergence; Niche; HSC; Hematopoietic stem cells; vWF; von Willebrand factor; TGC; trophoblast giant cell; CFC; Colony Forming Cells; EHT; endothelial-to-hematopoietic transition;