A comparison of short- and long-term prognoses between cases with and without antenatal corticosteroid administration in late preterm delivery: a nationwide population-based study.

Background: There is a paucity of information concerning the short- and long-term benefits and harm of antenatal corticosteroid administration and of expanded corticosteroid administration with dexamethasone in the late preterm period. Thus, we aimed to compare the effect on short-term respiratory complications, hypoglycemia, and long-term neurodevelopmental disorders in neonates born in the late preterm period between cases with and without corticosteroid administration and evaluate the difference in effects according to the type of corticosteroid administered.

Methods: This retrospective observational cohort study included all women who had a singleton delivery in the late preterm period between January 2007 and December 2015. We extracted data from Korea National Health Insurance claims and National Health Screening Program for Infants and Children databases. Primary short-term outcomes were in the late preterm period. Concerning short-term effectiveness for respiratory morbidity, dexamethasone administration in the late preterm period was associated with respiratory complications and hypoglycemia in neonates. Long-term outcomes were neurodevelopmental disorders in infants/children observed at follow-up among all neonates until the end of 2018.

Results: Of 57,963 women who delivered late preterm births during the study period, 1,255 (2.2%) had received antenatal corticosteroid administration in late preterm period. Dexamethasone administration was associated with a decreased risk of transient tachypnea (adjusted odds ratio [aOR] 0.66, 95% confidence interval [CI] 0.50-0.88) compared with no antenatal corticosteroid administration, but this effect was not observed in relation to betamethasone administration (aOR 0.69, 95% CI 0.42-1.14).

Conclusions: Dexamethasone administration in late preterm infants was associated with a decreased risk of transient tachypnea compared with no corticosteroid administration but this effect was not observed with betamethasone administration. However, antenatal corticosteroid administration in the late preterm period did not lower the risk of other respiratory complications nor increase the risk of hypoglycemia, with no effect on neurodevelopment regardless of the type used.