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Evidence summaries

Antenatal Corticosteroids for Fetal Lung Maturation for Women at Risk of Preterm Birth

A course of antenatal corticosteroids to the mother accelerates fetal lung maturation in women at risk of preterm birth and reduces the risk of neonatal death, respiratory distress syndrome and several other complications. Level of evidence: "A"

A meta-analysis cd004454 included 11 trials with 4 857 women between 27 and 30 weeks and 5 915 infants. There was no significant difference in the proportion of infants with a serious outcome (RR 0.92, 95% CI 0.82 to 1.04; 11 trials, n=5 893 infants). There was a reduction in the use of respiratory support in infants exposed to repeat prenatal corticosteroids compared with infants not exposed (RR 0.91, 95% CI 0.85 to 0.97; 10 trials, n=5 791). The number needed to treat (NNT) to benefit was 21 (95% CI 14 to 41) women/fetus to prevent one infant from needing respiratory support. Birth weight z-scores were lower in the repeat corticosteroid group (mean difference -0.12, 95%CI -0.18 to -0.06; 11 trials, n=5 902). Infants exposed to between 2-5 courses of repeat corticosteroids showed a reduction in both serious outcome and the use of respiratory support compared with infants exposed to only a single repeat course.

A Cochrane review [Abstract] 1 included 27 studies with a total of11 925 infants. Treatment with antenatal corticosteroids is associated with an overall reduction in neonatal death T1, respiratory distress syndrome, cerebroventricular haemorrhage, necrotising enterocolitis, respiratory support, intensive care admissions, and systemic infections in the first 48 hours of life. It did not increase risk to the mother of death (RR 0.98, 95% CI 0.06 to 15.50, n=6244), chorioamnionitis (RR 0.86, 95% CI0.69 to 1.08, n=8374) or endometritis (RR 1.14, 95% CI 0.82 to 1.58, n=6764).

Corticosteroids versus placebo or no treatment

OutcomeRelative effect(95% CI)Risk with control - Placebo or no treatmentRisk with intervention - Corticosteroids (95% CI)№of participants(studies)
Perinatal deathsRR 0.85(0.77 to 0.93)15.6%13.3%(12 to 14.6)2.3% fewer(3.6 fewer to 1.1 fewer)9833(14)
Respiratory distress syndromeRR 0.71(0.65 to 0.78)14.8%10.5%(9.6 to 11.5)4.3% fewer(5.2 fewer to 3.2 fewer)11183(27)
Intraventricular haemorrhageRR 0.58(0.45 to 0.75)3.3%1.9%(1.5 to 2.5)1.4% fewer(1.8 fewer to 0.8 fewer)8475(12)
Mean birthweight (grams)941 g to 2654 gmean difference 14.02 lower(33.79 lower to 5.76 higher)9551(19)

    References

    • McGoldrick E, Stewart F, Parker R et al. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth. Cochrane Database Syst Rev 2020;(12):CD004454.[PubMed]
    • Crowther CA, Middleton PF, Voysey M et al. Effects of repeat prenatal corticosteroids given to women at risk of preterm birth: An individual participant data meta-analysis. PLoS Med 2019;16(4):e1002771. [PubMed]

Primary/Secondary Keywords