Timing of Delivery for Pregnancies With Congenital Diaphragmatic Hernia

Abstract

Recent data published by the Congenital Diaphragmatic Hernia (CDH) Study Group suggested increased survival among infants with prenatally-diagnosed CDH born at early-term (37–38 weeks' gestation) compared with infants born at later term (39–41 weeks). These results contradict other published data. Moreover, the protective effects of early delivery on mortality became statistically significant only after an adjustment for birth weight (which was likely to overestimate the beneficial effects of early delivery). At present, no firm recommendation regarding the optimal timing of delivery of infants with CDH is possible. The aim of this study was to confirm the protective effect of an early-term delivery by comparing the gestational age-specific mortality patterns of term infants with and without isolated CDH delivered following the spontaneous onset of labor. The study population was 2089 singleton live births with isolated CDH born between 37 and 41 weeks of gestation; of these, 928 were born following vaginal delivery and were included in the final cohort. Log-binomial regression analysis assessed the effect of gestational age on mortality among CDH infants and adjusted the data for potentially confounding factors. With advancing gestational age (37 vs. 40 weeks), both neonatal and infant mortality decreased; neonatal mortality from 25.0% to 16.7% and infant mortality from 36.4% to 19.3%. Log-binomial regression analysis predicting risk of neonatal mortality showed a statistically significant trend of decreased risk with advancing gestational age: the relative risk for death was higher at 37 weeks versus 40 weeks (relative risk, 1.50; 95% confidence interval, 1.02–2.21). These findings suggest that there is no benefit of early-term delivery in lowering mortality due to CDH. This and other available evidence suggests that it may be premature to change clinical practice.