Contraction of the pelvis affects the mother and child in parturition in proportion to the degree of the narrowing. Besides this, the prognosis depends on the size of the child, its presentation, position, and attitude, the strength of the pains, the skill and surgical cleanliness of the operator, and the presence or absence of complications. Obstruction may bring about rupture of the uterus, septicemia, exhaustion and shock, pressure narcosis, or tears of the cervix or vagina. If the child's head becomes impacted the vagina and vulva may become even gangrenous. Pressure may cause areas of necrosis resulting in fistulas into the bladder, rectum, or between the uterus and the vagina. When the contracture is sufficient to let the fetus just engage, pressure may interfere with the placental circulation and kill the child. Compression of the vagus nerve may slow the child's pulse and asphyxiate it through lack of oxygen in the blood. The cord may prolapse. The pressure on the child's head may cause fatal intracranial hemorrhage, or effect permanent injury to the brain. Often it is extremely difficult to find out the best plan for delivering a woman who has a contracted pelvis. Where the conjugata vera is 9.5 cm. (3-5/8 inches) or above, Ludwig and Savor found that 75 per cent. were delivered without instrumental help. At 9 cm. (3-1/2 inches), 58 per cent. so end; at 8 cm. (3-3/16 inches), 25 per cent. Should the conjugata vera be less than 5-1/2 cm. (2-3/16 inches) in a flat pelvis, or 6 cm. (2-3/8 inches) in a generally contracted pelvis, this is an absolutely contracted pelvis according to the old standard, and the delivery must be by cesarean section, whether the child is living or dead. The minimal requirements have been gradually extended. In 1901 Williams of Johns Hopkins University advocated that the absolute indication for cesarean section be changed to 7 cm. in the generally contracted pelvis, and to 7.5 cm. in the simple flat pelvis. His opinion was accepted by Webster, Jewett, Edgar, and others. Now some obstetricians of authority extend the measurements to 8 cm. If the woman is seen before labor, or early in labor, cesarean delivery alone is done. When the uterus is infected it is usually necessary to remove it after taking away the child, because an infected uterus left in place causes death by sepsis, as a rule.