The validity of the observed‐to‐expected lung‐to‐head ratio in congenital diaphragmatic hernia in an era of standardized neonatal treatment; a multicenter study

OBJECTIVE: To assess the predictive value of observed-to-expected lung-to-head ratio (O/E LHR) for survival and chronic lung disease (CLD) in survivors of left-sided congenital diaphragmatic hernia (CDH) in an era of standardized neonatal treatment, and to evaluate the predictive value of the O/E LHR trajectory for survival. METHODS: This retrospective cohort study was performed in two high-volume CDH centers in the Netherlands in prenatally detected, isolated left-sided CDH patients born between 2008 and 2014. O/E LHR and liver position were determined using 2D-ultrasonography at three time points during gestation from 19 weeks onwards. Ultrasound measurements were performed on stored ultrasound data by one single experienced operator blinded to postnatal outcome. RESULTS: Of the 122 included cases, 77.9% survived of whom 38.9% developed CLD. A significant association was found between the first measured O/E LHR and survival and development of CLD in survivors. Prenatal liver position did not have additional predictive value. No significant association was found between the trajectory of the O/E LHR and survival. CONCLUSION: In an era of standardized neonatal treatment for neonates with CDH, the first measured O/E LHR per patient significantly predicts survival and development of CLD in survivors in isolated left-sided CDH infants.