(873) Timing of antenatal steroid administration in twin gestations

Objective: The administration of antenatal steroids to improve neonatal outcomes is common in situations of anticipated preterm delivery both before and after 34 weeks. Our objective was to evaluate maternal and neonatal outcomes in twin gestations delivered after 34 weeks.

Study Design: We conducted a retrospective cohort study of twin gestations delivered at > 34 weeks gestation within our health system from 2020-2021. Subjects were excluded if they delivered before 34 weeks gestation. Included subjects were categorized based upon presence and timing of antenatal steroid administration (< 34 weeks, > 34 weeks, or none). Our primary outcome was presence of respiratory distress syndrome. Secondary outcomes included other adverse neonatal outcomes, including use of surfactant, use of supplemental oxygen with a fraction of inspired oxygen of 30% for at least 24 hours, neonatal hypoglycemia, and birthweight < 10th percentile. Groups were compared via t-tests, chi-square analysis, Fisher’s exact test, and linear and logistic regression.

Results: 522 subjects were included, of which 374 (71.6%) did not receive steroids, 66 (12.6%) received steroids < 34 weeks, and 82 (15.7%) received steroids > 34 weeks. When controlling for other factors that differed among groups with p< 0.05, those receiving steroids < 34 weeks demonstrated significantly lower rates of respiratory distress syndrome (aOR 0.32, 95%CI 0.12-0.85), but higher rates of transient tachypnea of the newborn (aOR 2.42, 95%CI 1.16-5.04) when compared to those who did not receive steroids. This significant improvement was not noted in cases of steroids received > 34 weeks gestation. Additional neonatal complications were not significantly different between groups when controlling for other factors.

Conclusion: Rates of respiratory distress syndrome were significantly lower in twin gestations who received steroids < 34 weeks gestation, without similar significant improvement seen with steroid administration > 34 weeks gestation.