The association between cesarean birth and outcome in vertex presentation: relative importance of birth weight, Dubowitz scores, and delivery route.

The effect of the obstetrician's choice for delivery route on infant outcomes was studied in 17,260 mothers in labor, with the fetus alive at the onset of labor, in vertex presentation, and without major congenital anomalies. At birth weight categories, stratified by 500 gm increments, there was no improvement in intrapartum and neonatal mortality or in neonatal morbidity associated with the cesarean birth route. The major dependent variables important in neonatal outcome were birth weight and neonatal maturity. The association between cesarean section delivery and outcome in vertex presentations is limited. This information documents the need for prospective randomized and controlled studies with respect to proposed changes in birth route for the very low-birth weight fetus.