Figure 1.

Incidence of RDS by gestational age. These data offer an estimate of the gestational age-specific incidence of RDS in the postcorticosteroid era. The most likely explanation for the observed decrease in neonatal RDS over the past 30 years is the increased utilization of antenatal corticosteroids in women at risk for preterm birth prior to 34 weeks’ gestation, from 0% (data collected 1957–1963¹⁰) to 20% (data collected 1983–1986³) and finally to 84% (data collected 2003–2005¹¹).