Summary of findings 1. Neonatal and child outcomes: corticosteroids compared to placebo or no treatment for accelerating fetal lung maturation for women at risk of preterm birth.

Neonatal and child outcomes: corticosteroids compared to placebo or no treatment for accelerating fetal lung maturation for women at risk of preterm birth
Patient or population: infants born of women at risk of preterm birth Setting: hospitals settings in low‐, middle‐ and high‐resource countries Intervention: corticosteroids Comparison: placebo or no treatment
Outcomes	Relative effect (95% CI)	Anticipated absolute effects* (95% CI)			Certainty of the evidence (GRADE)	What happens
		Without Corticosteroids	With Corticosteroids	Difference
Perinatal death (composite of fetal death (in utero death) and neonatal death) № of participants: 9833 (14 RCTs)	RR 0.85 (0.77 to 0.93)	Study population			⊕⊕⊕⊕ HIGH	Corticosteroids reduce perinatal death compared with placebo or no treatment.
		15.6%	13.3% (12 to 14.6)	2.3% fewer (3.6 fewer to 1.1 fewer)
Neonatal death (infants born with signs of life who die within the first 28 days) № of participants: 10,609 (22 RCTs)	RR 0.78 (0.70 to 0.87)	Study population			⊕⊕⊕⊕ HIGH	Corticosteroids reduce neonatal death compared with placebo or no treatment.
		11.9%	9.3% (8.3 to 10.3)	2.6% fewer (3.6 fewer to 1.5 fewer)
Respiratory distress syndrome № of participants: 11,183 (26 RCTs)	RR 0.71 (0.65 to 0.78)	Study population			⊕⊕⊕⊕ HIGH	Corticosteroids reduce respiratory distress syndrome compared with placebo or no treatment. We did not downgrade for risk of bias (two trials) at high risk of bias due to lack of placebo in control) because sensitivity analysis removing those trials made very little difference to the effect estimate.
		14.8%	10.5% (9.6 to 11.5)	4.3% fewer (5.2 fewer to 3.2 fewer)
Intraventricular haemorrhage (IVH) № of participants: 8475 (12 RCTs)	RR 0.58 (0.45 to 0.75)	Study population			⊕⊕⊕⊝ MODERATE 1	Corticosteroids probably reduce intraventricular haemorrhage compared with placebo or no treatment. We did not downgrade for risk of bias (four trials infants) at high risk of bias due to lack of placebo in control groups) because sensitivity analysis removing those trials made very little difference to the effect estimate.
		3.3%	1.9% (1.5 to 2.5)	1.4% fewer (1.8 fewer to 0.8 fewer)
Mean birthweight (g) № of participants: 9551 (19 RCTs)	‐	The mean birthweight in the control group ranged from 941 g to 2654 g	‐	MD 14.02 lower (33.79 lower to 5.76 higher)	⊕⊕⊕⊕ HIGH	Corticosteroids result in little to no difference in mean birthweight compared with placebo or no treatment. We did not downgrade for risk of bias (two trials at high risk of bias due to incomplete outcome data) because sensitivity analysis removing those trials made very little difference to the effect estimate. We did not downgrade for imprecision because the confidence interval showed a difference at most on average of 33 g in weight, which is less than 10% of the lightest mean weight in any trial.
Developmental delay in childhood № of participants: 600 (3 RCTs). Age at follow‐up: 2 to 12 years.	RR 0.51 (0.27 to 0.97)	7.7%	4.0% (2.1 to 7.5)	3.8% fewer (5.7 fewer to 0.2 fewer)	⊕⊕⊕⊝ MODERATE 2	Corticosteroids probably lead to a slight reduction in developmental delay in childhood compared with placebo or no treatment. Additionally, in three studies (778 children) it was uncertain if corticosteroids had any effect on intellectual impairment (RR 0.86, 95% CI 0.44 to 1.69). In two studies (166 children) it was uncertain if corticosteroids had any effect on the risk of visual impairment (RR 0.55, 95% CI 0.24 to 1.23) and in one study (82 children) it was uncertain if corticosteroids have any effect on hearing impairment (RR 0.64, 95% CI 0.04 to 9.87). Another study reported no children with hearing impairment in either group (84 children).
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio.
GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

¹ Downgraded one level for indirectness: in some trials only a subset of infants were screened for IVH; some trials diagnosed IVH at postmortem only.

² Downgraded one level for risk of bias: unclear randomisation, allocation concealment, incomplete outcome data and selective reporting