Under normal circumstances, the placenta is delivered automatically after the birth of a child, and the period of placenta delivery is the third stage of labor. After delivery of the fetus, the pressure in the uterine cavity decreases so much that the placenta cannot shrink accordingly and becomes misaligned with the uterine wall, resulting in abruption. There are four signs of placental abruption: first, the uterine body becomes hard and spherical. Secondly, the placenta descends to the lower part of the uterus and the umbilical cord that is exposed at the vaginal opening will lengthen on its own. Third, there will be a small amount of vaginal bleeding. Fourthly, if the midwife uses the ulnar side of the palm of her hand above the pubic symphysis and presses gently on the lower uterine segment, the uterus will rise, but the exposed cord will no longer retract. These signs prove that the placenta has been aborted. After placenta abruption, you can hold the fundus of the uterus with your left hand during contraction and press gently, while your right hand can pull the umbilical cord gently to help deliver the placenta.