Abstract:The process of pregnancy includes several irreversible steps from embryo implantation, decidualization, placenta development to final delivery. The successful occurrence of embryo implantation requires the synchronization between implantation-competent blastocysts and receptive uterus. The establishment of uterine receptivity is under the dynamic regulation of ovarian progesterone and oestrogen through their respective nuclear receptors, which cooperate with various transcription factors, cytokines and growth factors to induce the orderly proliferation and differentiation of uterine epithelial and stromal cells.