The uterus has greatly decreased in size, the fundus now lying below the umbilicus where it may be felt as a firm, solid mass. The uterine contractions are resumed in the course of a few moments and as they persist, the uterus grows smaller, thereby greatly decreasing the area of placental attachment. As the placenta is non-contractile it cannot accommodate itself to this decreased area of attachment, and so is literally squeezed from its moorings. It is then gradually forced down into the lower uterine segment where it may be located by the distension of the abdominal wall which it produces just above the symphysis. After the separation of the placenta is complete the uterus rises in the abdominal cavity until the fundus is felt above the umbilicus. The placenta, finally, may be completely expelled spontaneously, or expressed by slight pressure made upon the fundus by the accoucheur. The placental detachment may begin at the centre, the area of separation spreading to the margin, or the detachment may start at the margin of the placenta and extend toward the centre. Either is normal. These two modes of placental separation are named the Schultze and the Duncan, respectively, from the men who first described them. (Fig. 71.) In the Schultze mechanism, which occurs most frequently, the separating process begins at the centre of the placenta and the glistening fetal surface appears at the vaginal outlet. In this case there is practically no bleeding during the third stage as the inverted placenta blocks the vagina and holds back the blood. In Duncan’s mechanism the detachment begins at the margin, the placenta rolls upon itself and presents at the outlet by its roughened maternal surface and there is usually slight but continuous bleeding from the time the separation begins. When the placenta is delivered, the collapsed membranes trail after it like a tapering cord. A good deal of blood is lost at the time of the placental expulsion and immediately afterwards, but this profuse bleeding usually subsides in a few moments. Although the loss of blood may be as much as 500 cubic centimetres without its being regarded as serious, the average amount is about 350 cubic centimetres. The patient has been through a severe ordeal and at the end of the third stage of labor she is usually tired out and cold. CHAPTER XII THE NURSE’S DUTIES DURING LABOR The extent of the nurse’s helpfulness during labor, both to the patient and to the doctor, will depend very largely upon the intelligence with which she grasps what is taking place and upon her own attitude, as an individual, toward the patient and the miraculous event which approaches. Important as is the preparation of the room and dressings, this other factor is almost equally influential.