Oxygen targets for preterm infants.

Retinopathy of prematurity (ROP) was first observed soon after the widespread introduction of oxygen therapy into neonatal care. Early trials suggested that restricting oxygen supplementation could reduce ROP without other consequences, but when oxygen restriction became widespread, increased mortality was observed. These observations were made before continuous monitoring of oxygenation was possible. New trial evidence from masked randomized controlled trials of different pulse oximeter oxygen saturation (SpO2) target ranges now shows that targeting lower SpO2 levels reduces ROP but is associated with significantly increased mortality. These results illustrate the importance of randomized trials because, prior to these recent studies, trends in practice based on observational data were favouring lower SpO2. Follow-up data may yet further inform clinical practice.