Primary Study Of Human Endometrial Receptivity

Endometrial receptivity is a self-limited period in which the endometrium acquires a functional and transient ovarian steroid-dependent status that allows blastocyst adhesion. Termed as "the window of implantation", this specific period opens 4-5 days after the preovulatory endogenous luteinizing hormone(LH) surge , exogenous human chorionic gonadotropin(hCG)administration or progesterone production and closes after 9-10 days. During the process of implantation it absolutely requires synchronized development of the blastocyst to implantation competency, differentiation of the uterus to the receptive state, and a reciprocal dialogue between the blastocyst and endometrium. LH surge plays a substantial role in molecular regulation of oocyte maturation, embryos development and the dialogue between human embryo and endometrium in the implantation process.Selecting the most viable embryos and scientific knowledge on the endometrial receptivity process is fundamental for the understanding of human reproduction.Nowadays, the primary criteria for embryo selection after human IVF are the morphological assessments and embryo-derived biochemical markers. Selecting an embryo based upon its grading score has its limitations, e.g. qualitative grading does not necessarily indicate embryo viability. A number of endogenous factors are attributed to the regulation of preimplantation embryo development and implantation, and may be used as indicators of embryo viability. In the study, we investigated the distribution of LH in human oocytes and preimplantation embryos further on the basis...