Tan YW, et al. - Researchers compared the mean oxygenation index on day1 (MOId1) with the best OI on day1 (BOId1) in predicting 30-day mortality in congenital diaphragmatic hernia (CDH). Further, they determined the association of serial OIs in the first 48 h after birth and preoperative OI (PreOp-OI) with optimal timing of surgery, ventilation requirement and hospital stay in infants with CDH. They retrospectively reviewed the medical records of infants with antenatally diagnosed CDH during 2009–2015, identifying both MOId1 and BOId1 as highly predictive of mortality in CDH. The timing of surgery was poorly predicted using oxygenation indices in the first 48 h. They suggest PreOp-OI <3 as a cutoff for optimal timing for surgery in infants for CDH repair.