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.