Does observed vs expected lung head ratio correlate with neonatal survival in infants with congenital diaphragmatic hernias?

To investigate whether observed vs expected (O/E) lung–to–head ratio (LHR) correlates with neonatal survival in infants with congenital diaphragmatic hernia (CDH). Secondary goal was to correlate O/E LHR with Oxygenation index (OI) in the first 12 hours of life