Catastrophic complications of previous cesarean section.

Of 711 patients who were delivered after one or more previous cesarean sections, 17 (2.4%) had an extremely serious complication. Uterine rupture and placenta previa or placenta accreta with accompanying hemorrhage were the major contributors to mortality and major morbidity. Nine uterine ruptures occurred, including five associated with labor with a low transverse uterine scar and one with an unknown scar (1.4% of trials of labor). There were two cases of placenta previa and five with varying degrees of placenta accreta. The nature and frequency of the observed complications emphasize the potentially serious remote consequences of cesarean section.