Cesarean delivery in the United States, 1990.

Information now available on method of delivery from birth certificates confirms past findings on the groups at highest risk of cesarean delivery and greatly expands our knowledge of the demographic and health characteristics associated with cesarean delivery. Mothers who live in the South, who are in the oldest years of childbearing, having their first birth, married, or who have high educational attainment are all at increased risk of a cesarean delivery. Very short gestations, low or high birthweights, multiple delivery, the presence of certain complications of pregnancy, labor and/or delivery, abnormal conditions of the newborn, and the use of some obstetric procedures are also associated with elevated cesarean rates. Several recent studies (28,29) have concluded that advanced maternal age in and of itself may be an independent risk factor for cesarean delivery, due to physician and patient concern over pregnancy outcome for older women. Many of the characteristics examined in this study are highly related to maternal age (for example, marital status and educational attainment). Therefore, for these variables, mother's age is also taken into account to determine if age itself is the underlying reason for differences in rates of cesarean delivery. The importance of the role of maternal age in the risk of cesarean delivery is clearly demonstrated throughout this report: Older mothers are more likely to deliver by cesarean regardless of race, Hispanic origin, parity, marital status, or educational attainment. The overall rate of cesarean delivery is only slightly lower for black than for white mothers (22.1 percent compared with 23.0 percent), despite the generally lower educational attainment of black mothers and the higher percentage who are unmarried or in their teen years, all factors that tend to substantially lower the risk of cesarean delivery. However, there are many offsetting factors that tend to raise the cesarean rate for black mothers. A relatively high proportion of black births occur in the South, which has the highest cesarean rate of all regions; the incidence of low and very low birthweight is far higher for black births; and premature delivery is twice as frequent for black babies. Also, although rates of cesarean delivery for most medical risk factors, complications of labor and or delivery, and abnormal conditions of the infant are about the same for both races, the incidence of a number of these conditions is substantially higher for black mothers and babies, and that has the effect of increasing the overall cesarean rate for black mothers.(ABSTRACT TRUNCATED AT 400 WORDS)