Chronic lung disease (bronchopulmonary dysplasia) remains a major problem for neonatologists caring for very preterm infants, with rates in Europe varying from 10% in one Italian region to 25% in the northern region of the UK in the Models of Organizing Access to Intensive Care for Very Preterm Births (MOSAIC) cohort study1; infants in this study had gestational ages ranging from 23 to 31 weeks. Similar or even higher rates are found in the USA, with a recent study reporting a rate of bronchopulmonary dysplasia of 43% of survivors at 22–28 weeks' gestation.2 As the pathogenesis of neonatal chronic lung disease is thought to involve a perinatal inflammatory process,3 corticosteroid treatment has been proposed as a rational intervention for both prevention and therapy.4

In the late 1960s and early 1970s, hydrocortisone was given to preterm infants with respiratory distress syndrome with the aim of modifying the course of this disease. No acute benefits were noted, but follow-up studies pointed towards potentially harmful effects on the developing central nervous system. Dexamethasone was first used to treat infants with bronchopulmonary dysplasia in 1978, but the study was never published in full. In the 1980s, two small studies of …