The question of removing the uterus solely to prevent the danger of subsequent deliveries differs from the condition just considered. If the woman has had a cesarean delivery for an absolutely narrow pelvis, her subsequent deliveries must be by the same method. After a cesarean section there is more or less danger of rupture at the scar in other labors. Some think the danger is greater if the placenta becomes implanted on the scar; others think this implantation does not weaken a good scar. If the convalescence after the cesarean section already done has been abnormal, the prognosis for rupture is not good. Where there has been an abnormal convalescence, each new pregnancy must be watched closely, and often an early subsequent cesarean is indicated to prevent rupture. No matter how well the section has been done, latent gonorrhea may prevent perfect healing of the wound. Twins, hydramnios, and overtime gestation are other causes of rupture. The tendency with obstetricians in the future will probably be to do the section toward the cervical end of the uterus; and as the uterus is thinnest there, it might be thought that it will be more likely to break, but Spalding[110] found the contrary true--the rupturing was usually in the thick part of the uterus. Version, high forceps, uterine tampons, hydrostatic bags, and pituitary extract should be avoided where an old cesarean scar exists, but Vogt and Kroback have done version a few times without rupture. Vogt had one patient with a true conjugate of 6-3/4 cm. (2-8/16 inches) to 7 cm. (2-3/4 inches). She was delivered in the first three labors by craniotomy; in the fourth by version; in the fifth and sixth by cesarean section; in the seventh she had twins one of which was born spontaneously; in the eighth by version and perforation of the after-coming head; in the ninth she refused operation and was delivered spontaneously. Skilful operators have the fewest ruptures after cesarean delivery. Olshausen had one in 120 cases, Leopold none in 232 cases, Schauta none in 177 cases, Küstner none in 100 cases. Olshausen, in a series of 29 cases, operated on two patients twice and upon three patients three times. As early as 1875, Nancrede of Philadelphia had operated the sixth time on the same woman. In such cases the uterus is commonly so broadly attached by adhesions to the belly-wall that it is opened without getting into the peritoneal cavity. In 150 cases of repeated section collected by Polak in 1909 the mortality was only 5 per cent.