Rds and postnatal surfactant were found on subgroup analyses to have significant reductions in mortality, severity of respiratory dis- tress, and air leaks when compared with subgroups that received neither steroids nor surfactant, antenatal ste- roids only, or surfactant only.50–52 This finding corroborates evidence from an- imal models of RDS that the combina- tion of antenatal steroids and postnatal surfactant improves lung function more than either treatment alone.53–55