Antenatal Corticosteroids and Outcomes of Small-for-Gestational-Age Neonates.

OBJECTIVE

To assess the association of antenatal corticosteroids and neonatal outcomes of preterm small-for-gestational-age (SGA) neonates and estimate whether the association is similar to that observed in appropriate-for-gestational-age (AGA) neonates.

METHODS

We conducted a retrospective cohort study using data collected on singleton neonates born between 24 0/7 and 33 6/7 weeks of gestation and admitted to tertiary neonatal units in Canada between 2010 and 2014. Outcomes of SGA neonates (birth weight less than the 10th percentile) who received antenatal corticosteroids 1-7 days before birth (n=698) were compared with those of SGA neonates who did not receive antenatal corticosteroids (n=220). A similar comparison was performed between AGA neonates (birth weight between 10th and 90th percentile) who received antenatal corticosteroids 1-7 days before birth (n=3,781) and AGA neonates that did not receive antenatal corticosteroids (n=1,868). The association of antenatal corticosteroid exposure with outcomes was assessed using multivariable logistic regression and adjusted odds ratios (ORs) were compared between SGA and AGA groups.

RESULTS

Of the 6,567 neonates eligible for the study, 918 (14.0%) were SGA. Women in the SGA group who were exposed to antenatal corticosteroids had a lower rate of neonatal death (7% compared with 12%, P=.01) compared with those not exposed to antenatal corticosteroids, whereas the rate of composite outcome was similar between the two groups (28% compared with 30%, P=.56). After adjustment for potential confounders, exposure to antenatal corticosteroids 1-7 days before birth was associated with beneficial effects among both the SGA and AGA groups with similar reduced odds of neonatal death (SGA: adjusted OR 0.29 [95% confidence interval (CI) 0.15-0.57] compared with AGA: adjusted OR 0.40 [95% CI 0.29-0.54], P=.40), composite outcome (SGA: adjusted OR 0.53 [95% CI 0.33-0.87] compared with AGA: adjusted OR 0.51 [95% CI 0.42-0.62], P=.85), need for mechanical ventilation (SGA: adjusted OR 0.60 [95% CI 0.39-0.91] compared with AGA: adjusted OR 0.54 [95% CI 0.46-0.64], P=.70), and severe brain injury (SGA: adjusted OR 0.42 [95% CI 0.22-0.84] compared with AGA: adjusted OR 0.39 [95% CI 0.30-0.51], P=.80). Similar reduction in the odds of neonatal death was observed in the subgroup of neonates with birth weight less than the fifth percentile for gestational age and sex: adjusted OR 0.38 (95% CI 0.16-0.92).

CONCLUSION

For SGA preterm neonates, exposure to antenatal corticosteroids 1-7 days before birth was associated with decreased odds of neonatal mortality and morbidity similar in magnitude to that observed among AGA neonates.