Mode of delivery and perinatal results in breech presentation

Our purpose was to evaluate the outcome of deliveries with fetuses in breech presentation at labor and to compare the results by route of delivery. Specially reviewed were fetuses weighing > or = 1500 gm.

An observational study of consecutive cases of all singleton pregnancies and twin pregnancies with the first fetus presenting in breech delivered at Chicago Lying-In Hospital from July 1980 to December 1987 was performed. Crude perinatal mortality and effect of mode of delivery (cesarean vs vaginal) by weight were compared after correction for nonpreventable causes. A further correction was made for fetuses weighing > or = 1500 gm by excluding all cases of fetal distress from the cesarean section group. All clinically relevant factors were evaluated. Statistical methods included comparison of frequencies in the two groups by chi 2 and Fisher exact tests and comparison of means by two-sample t tests.

Of 21,380 deliveries, 843 (3.9%) presented by the breech. Forty-four percent were delivered vaginally; 8.4% were first twins. There were 51% preterm infants, and 24% had clinical distress. Crude perinatal mortality was 24%; 8% stillborns, 10% from prematurity, and 6% from other causes, including lethal congenital malformations. The corrected perinatal mortality was 15%. Vaginal deliveries had a higher 5-minute depression rate (32% vs 24%) and corrected perinatal mortality (23% vs 9.6%); however, fetal weights were significantly lower. There were no differences in outcomes for newborns weighing > or = 1500 gm by route of delivery; all five neonatal deaths in this subgroup occurred among the abdominal deliveries.

The very poor perinatal outcomes in breeches are primarily related to factors other than breech presentation. Route of delivery for infants weighing > or = 1500 gm does not influence neonatal outcome; thus cesarean section solely for breech presentation in this subgroup does not appear to be justified.