Cesarean Section in Term Breech Presentations: Do Rates of Adverse Neonatal Outcomes Differ by Hospital Birth Volume?

Abstract

In the United States, the majority (86%) of infants in breech presentation is delivered by cesarean, but some still have adverse neonatal outcomes. This study asked whether adverse outcomes after cesarean delivery at term differ according to the volume of such births at a given hospital. This population-based cohort study used Missouri birth certificate data from 10,106 singleton term infants (37 or more weeks gestation) born from 1993 to 1999 who had birth weights from 2500 to 3999 g and were in breech presentation. Infants with congenital abnormalities, growth restriction, or macrosomia, and all multiple gestations and preterm births were excluded. Participating hospitals were divided into low-, medium-, and high-volume terciles based on the median number of yearly deliveries over the period of study (<1034, 1035-2236, and 2237-6474 deliveries per year, respectively). The proportions of study infants born at low-, medium-, and high-volume hospitals were 38%, 28%, and 33%, respectively. The rates of any adverse outcome during the period under review were, respectively, 18, 15, and 6 cases per 1000 deliveries at low-, medium-, and high-volume hospitals. Neonatal deaths were relatively rare in all groups. After adjusting for maternal educational level, adverse outcomes were collectively more frequent in low- and medium-volume hospitals that at high-volume institutions. The respective odds ratios for low- and medium-volume hospitals compared with high-volume centers were 2.7 (95% confidence interval [CI], 1.6-4.5) and 2.4 (95% CI, 1.4-4.1). The odds ratios for adverse outcomes were significantly higher for parous women having a repeat cesarean section at a medium-volume hospital and for nulliparous mothers having primary cesareans at low- and medium-volume hospitals. These findings suggest that parturients whose fetuses are in breech presentation incur an increased risk of an adverse outcome after cesarean delivery at hospitals where there are fewer than 2200 births per year. Not enough is known about the factors affecting this finding to recommend transferring prospective mothers to large-volume hospitals.