sunitafeme
Embryo–endometrial dialogue has led to the identification of a ‘window of implantation’. The implantation window is characterized by changes to the endometrium cells, which aid in the absorption of the uterine fluid. These changes bring the blastocyst nearer to the endometrium and immobilize it. The first step of implantation is the formation of foetal–maternal interface. Next crucial step is invasion of the embryo into the endometrium.