The effects of antenatal corticosteroids on RDS were assessed using data from 15 trials. The numbers of participants were presented in potentially overlapping subgroups rather than totals. Five trials (n=837) assessed the effects of corticosteroid administration before trial entry on neonatal deaths (n=837), 4 trials (n=793) assessed the effects on IVH, and 3 trials (n=487) assessed the effects upon NEC. In addition, 7 trials assessed the effects on maternal infection and on foetal or neonatal infection. Again, the numbers of participants were presented in potentially overlapping subgroups rather than totals for these outcomes.
Compared with controls, antenatal corticosteroid administration to women who had rupture of membranes at trial entry or pre-labour was associated with a combined reduction in the RR of RDS (RR 0.59, 95% CI: 0.48, 0.71). In addition, the RRs of respiratory distress following rupture prior to trial entry (RR 0.56, 95% CI: 0.46, 0.70) and pre-labour (RR 0.62, 95% CI: 0.49, 0.78) alone were reduced. Antenatal corticosteroid administration to women who ruptured between 24 and 48 hours prior to onset of labour was also associated with a reduction in the RR of RDS (RR 0.64, 95% CI: 0.46, 0.0.88) compared with controls, whereas antenatal corticosteroid administration to women who had ruptured at least 48 hours prior to onset of labour was not (RR 0.68, 95% CI: 0.35, 1.33). The authors also report individual analyses for one trial included in the review. None of the analyses demonstrated a reduction in the RR of RDS in comparison with the controls. The combined data for the effects of antenatal corticosteroid administration on neonatal deaths revealed that, compared with the controls, there was no reduction in the RR (RR 0.68, 95% CI: 0.43, 1.07) regardless of the duration of membrane rupture. The administration of antenatal corticosteroid reduced the RR of IVH (RR 0.47, 95% CI: 0.31, 0.70) and NEC (RR 0.21, 95% CI: 0.05, 0.82) among infants, compared with controls.
Analyses of the effects upon maternal (RR 0.86, 95% CI: 0.61, 1.20) and infant (RR 1.05, 95% CI: 0.66, 1.68) infection suggest that antenatal corticosteroid administration does not increase the risk of these complications compared with controls. The subgroup analyses reported do not alter the findings.