Population-based study on antenatal corticosteroid treatment in preterm small for gestational age and non-small for gestational age twin infants

Objectives: To assess the associations between antenatal corticosteroid use (ACU), mortality and severe morbidities in preterm, twin neonates and compare these between small for gestational age (SGA) and non-SGA twins. Materials and methods: Population-based study using data collected by the Israel National Very Low Birth Weight infant database from 1995 to 2012, comprising twin infants of 24–31 weeks' gestation, without major malformations. Univariate and multivariable logistic regression analyses were performed. Results: Among the 6195 study twin infants, 784 were SGA. Among SGA neonates, ACU were associated with decreased mortality (23.9% vs. 39.2%, p < 0.0001) and composite adverse outcome including mortality or severe neonatal morbidity (43.8% vs. 56.8%, p = 0.0015), similar to the effect in non-SGA neonates (mortality 13.0% vs. 24.5%, p < 0.0001; composite outcome 34.2% vs. 44.8%, p < 0.0001). In the multivariable logistic regression analyses, ACU were associated with an almost 50% reduced mortality risk among SGA twin neonates (OR = 0.52, 95% CI 0.31–0.88) similar to the effect in non-SGA twin neonates (OR = 0.56, 95% CI 0.45–0.70), P_interaction= 0.69. Composite adverse outcome risk was also reduced in SGA (OR = 0.78, 95% CI 0.50–1.23) and non-SGA groups (OR = 0.78, 95% CI 0.65–0.95), P_interaction= 0.95. Conclusions: ACU should be considered in all mothers with twin gestation, at risk for preterm delivery at 24–31 weeks, in order to improve perinatal outcome.