Compléter embryo developmentVersion en ligne there are many stages in embryo development par izzati razali 1 endometrium vein placenta active pregnancy cervix Blood movements nutrients placenta delivery The process from development of embryo to the delivery of a baby . 1 . Trophoblast mingles with the and forms the . 2 . from the embryo travels to the placenta through arteries of the umbilical cords and returns via umbilical . 3 . First 2 to 4 weeks , the embryo obtains directly from the endometrium . 4 . The uterus grows enough for the to become obvious . 5 . The mother may feel fetal . 6 . The fetus grow and is very . 7 . Thinning and opening of the , or dilation . 8 . Expulsion or of the baby . 9 . Delivery of the .