Risk factors associated with mortality in newborn infants with congenital diaphragmatic hernia

Introduction. Morbidity and mortality are high in congenital diaphragmatic hernia. Some tools help to predict survival, both prenatally (observed/expected lung-to-head ratio [OE-LHR], presence of the liver in the chest) and postnatally (Congenital Diaphragmatic Hernia Study Group [CDHSG] score). Our objective was to identify the risk factors associated with mortality and estimate the risk-adjusted mortality in the prenatal period in the subgroup of patients with isolated left-sided hernia. Population and methods. Retrospective and analytical study of patients born at Hospital Italiano de Buenos Aires between 2011 and 2018. A multivariate analysis was done to assess mortality-associated risk factors. For risk-adjusted mortality in the prenatal period, the ratio between the observed mortality and the mean expected mortality based on the OE-LHR was estimated. Results. A total of 53 patients were included. Their median gestational age was 38 weeks, and their mean birth weight was 3054 g. Isolated hernia was observed in 73 % of patients. Overall mortality was 45 %, and higher in patients with associated malformations. In the multivariate analysis, the presence of severe pulmonary hypertension estimated by postnatal echocardiogram was independently associated with mortality (adjusted odds ratio: 6.4, 95 % confidence interval: 1.02-40). The observed overall mortality in patients with isolated left-sided hernia was similar to that expected (ratio: 1.05). Conclusion. Overall mortality was similar to that expected based on the OE-LHR. In our population, severe pulmonary hypertension after birth was a determining factor of mortality.