Uterine Receptivity: The Status of Uterus for Implantation

Abstract

Embryo implantation requires an implantation-competent blastocyst and a receptive uterus. Uterine receptivity refers to a state in which the uterus is favorable for embryo implantation, which only lasts for a limited time period known as “the window of implantation”. Disturbances during the establishment of uterine receptivity would lead to adverse pregnancy outcomes. As the gateway for embryo implantation, the uterine luminal epithelium undergoes prominent differentiation under the coordination of ovarian estrogen and progesterone to attain receptivity. This article introduces the concept of uterine receptivity, and summarizes the hormonal environment for uterine receptivity, the morphological changes and molecular basis of uterine epithelial differentiation, as well as the epithelial-stromal and embryonic-epithelial interactions during uterine receptivity establishment.