Background Systemic corticosteroids as the frontline treatment of respiratory distress syndrome (RDS) in preterm infants are associated with adverse effects on growth and neurodevelopmental outcome, but the pulmonary administration of steroids may help prevent the development of bronchopulmonary dysplasia (BPD) without these side effects.

Objectives To evaluate the efficacy and safety of pulmonary application of corticosteroids in preterm infants with RDS.

Methods MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, the WHO’s International Clinical Trials Registry and grey literature were searched with no restriction on date and language of publication from inception to May 2016. Using a random-effect model, we pooled data from randomised controlled trials (RCTs) comparing inhaled or endotracheal corticosteroids with the standard of care, placebo or no other intervention in preterm infants with RDS.

Results We identified 873 potential citations and included 12 unique RCTs. Pulmonary corticosteroid therapy was associated with a significant reduction in the composite outcome of BPD or death (relative risk (RR) 0.85, 95% CI 0.76 to 0.96). Pulmonary application of corticosteroids significantly reduced the incidence of patent ductus arteriosus (PDA) (RR 0.82, 95% CI 0.74 to 0.92) and pneumonia (RR 0.57, 95% CI 0.35 to 0.92). There was no evidence of a significant difference regarding the risk of neurodevelopmental impairment or other side effects.

Conclusions Pulmonary administration of corticosteroids reduces the incidence of BPD or death, pneumonia, PDA without causing any major side effects in preterm infants with RDS.