The recent reaffirmation of the National Collaborative Study and similarly designed studies that reject the efficacy of corticosteroid administration to patients with preterm premature rupture of the membranes prompted us to reevaluate patients screened for inclusion in our recently reported series. Fetal maturity studies performed upon 135 consecutive singleton pregnancies of 26–35 weeks' gestation produced values consistent with fetal immaturity in only 6% (eight of 135) cases. The percentage that was immature did not change substantially when gestational age was restricted to those less than 34 weeks' gestation (11%; eight of 73). This information, from an institution whose patients were members of the original collaboration, suggests that the design of that study (which did not require maturity studies in gestations less than 34 weeks) and other studies with similar or less restrictive enrollment criteria may have permitted the inclusion of a significant number of fetuses in whom pulmonary maturity was already present, thus reducing the likelihood that differences in outcome could be demonstrated between groups.