Fertilização e reconhecimento materno da gestação (revisão de literatura).

Abstract

The fusing of oocyte with a spermatozoo, in the oviduct, will imply in the development of an embryo, then, the fertilization is the union of feminine and masculine gamete, thus forming an only cell, call of zygote or egg. The egg phase or zygote extends since the fecundation until the implantation of the zygote in the uterus. In this phase the egg is submmited for some transformations that go since the period of training of a cell until the one of blastocyst come out, arriving at the uterine light after the two three days of the fertilization, where it remains until its implantation. When blastocyst reach the endometrium to it, has beginning the embryonic phase, which is characterized by the fast growth - the tissues, and systems develop themselves and the main characteristics of the body start to be recognized. It is in this phase that happens the maternal recognition of the pregnancy, where conceptus, must signal its presence it maternal organism and to block the regression of the corpus luteum (CL), called luteolisis, with the purpose to keep production of progesterone. The result of the predominance of the progesterone is the maintenance of the pregnancy. So that the regression of the CL does not occur, conceptus synthetizes and private steroid and/or proteins, which serve to modulate the synthesis and/or the release of F2a prostaglandin (PGF2a) from the uterus, thus preventing the regression. Therefore, the maternal recognition of the gestation can be defined as being the critical period in which the to signal for conceptus occurs, that it luteolisis blocks, thus allowing the establishment of the gestation.