The frequency of complications in cesarean and noncesarean deliveries, 1970 and 1978.

National Hospital Discharge Survey data, collected by the National Center for Health Statistics, were used to examine complications associated with cesarean and noncesarean deliveries in the years 1970 and 1978. Cesarean deliveries comprised 5.5 percent of all deliveries in 1970 and 15.2 percent in 1978. Two-thirds (68.4 percent) of the 1970 and 82.1 percent of the 1978 cesarean deliveries involved specified complications compared with only 14.6 percent of the 1970 vaginal deliveries and 17.8 percent of the 1978 vaginal deliveries. More than one-fourth of the 1970 and 1978 cesarean deliveries, but less than 1 percent of the vaginal deliveries, were preceded by a cesarean section delivery. From 1970 to 1978, there was both a rise in breech presentations and a shift toward surgical management of them. Also, cesarean deliveries were associated with placenta previa, fetopelvic disproportion, prolonged labor, and premature rupture of membranes. Several competing explanations have been offered for the rise in complication rates and in cesarean delivery rates.