The very purpose of the endometrium is human reproduction, a process made possible by the interaction between immune and endometrial cells. While endometrial cells seem to be responsible for immune cell infiltration, they also have the capacity to limit the infiltration and activity of immune cells. This cellular interaction is prominent not only during the implantation window, but also during labor. Indeed, the proper interaction between the endometrium and trophoblast and immune cells enables proper implantation and also determines placental detachment. The molecular alterations observed during implantation are well documented; however, the molecular basis of placental abruption still remains unclear. The proper placental detachment during the third stage of labor is a crucial event in the overall course of labor, whereas placental abruption leads to severe complications. The place where trophoblast and immune cell interaction begins during Fallopian tube gestation without the participation of endometrial cells is the tubal wall. This difference is most consequential during tubal rupture. The determination of the mechanisms responsible for endometrial participation in immune tolerance during pregnancy could have important clinical consequences and may prove significant in the development of immunotherapy.