The Effect of Incompletely Administered Antenatal Corticosteroids on Neonatal Pulmonary Outcomes in Late Preterm Infants

Abstract

Purpose: Recent obstetric guidelines recommend the administration of antenatal corticosteroids in pregnant women at risk of delivering infants at a gestational age between 34 and 36 weeks. We examined the effect of incompletely administered antenatal corticosteroids on the neonatal pulmonary outcomes in late preterm infants.Methods: Late preterm infants (34<sup>+0</sup> to 36<sup>+6</sup> weeks gestational age) born at the Seoul National University Bundang Hospital from January 2019 to June 2020 were retrospectively enrolled. We excluded multiple births except twins, those with major congenital anomalies, deaths, or transfers to other hospitals. An incomplete course of antenatal corticosteroids was defined as one in which the first or the second dose of betamethasone was administered within 24 hours before delivery. The rates of neonatal pulmonary morbidities were compared between late preterm infants given incomplete courses antenatal corticosteroids and their peers who not given antenatal corticosteroids; these morbidities included respiratory distress syndrome and transient tachypnea of the newborn, assisted ventilation including invasive mechanical ventilation, nasal continuous positive airway pressure and high-flow nasal cannula, and admission to neonatal intensive care unit.Results: Logistic regression models were constructed while adjusting for factors which were significant in bivariate models. After adjusting for baseline maternal and neonatal characteristics, we found no significant differences in the rates of neonatal pulmonary morbidities, assisted ventilation, or admission to the neonatal intensive care unit between late preterm infants who received incomplete antenatal corticosteroid therapy and their peers who were not given any antenatal corticosteroids.Conclusion: Incompletely administered antenatal corticosteroids did not significantly alter the neonatal pulmonary outcomes in late preterm infants.