Surfactant trials that proved efficacy were performed at a time when an- tenatal steroid therapy was given in- frequently.43 By the late 1990s, most mothers of preterm infants born at less than 30 weeks’ gestation had re- ceived antenatal steroids (58% to 92%).44–46 Antenatal steroids signifi- cantly reduce mortality (RR 0.62; 95% CI 0.51–0.77; NNTB 23), RDS (RR 0.65; 95% CI 0.47–0.75; NNTB 12), and sur- factant use in preterm infants (RR 0.45; 95% CI 0.22–0.93; NNTB 9),47 most consistently in those born between 28 and 34 weeks’ gestation.