[Participation of hormones and regulating factors in implantation and development of the fetoplacental unit].

Although the embryo has a genetic program of its own development in order that development and embryonic differentiation take place, as well as normal gestation, a series of coordinated interactions between embryo and the mother, should be established; which are mediated by chemical messengers, autocrine, paracrine and endocrine. In this study, hormonal participation and regulating factors of implantation, and the feto-placental unit development, are analyzed.