Effect of Antenatal Dexamethasone on Respiratory Distress in Late Preterm Infants: Results from the First Vietnamese Matched Cohort Study

Abstract BackgroundRespiratory distress (RD) is one of the leading causes of early neonatal morbidity and mortality in late preterm infants (LPIs) worldwide. This study aimed to evaluate the effect of antenatal dexamethasone on the RD rate in preterm newborns between 34 0/7 weeks and 36 6/7 weeks of gestation.MethodsThis was a prospective cohort study of 78 women with singleton pregnancy who were in threatened preterm birth and had not received prior dexamethasone who were admitted between 34 0/7 weeks and 36 6/7 weeks at Hue University of Medicine and Pharmacy Hospital from June 2018 to May 2020. The matched control group (no dexamethasone) included 78 pregnant women with threatened late preterm births who were at similar gestational ages and estimated fetal weights as the treatment group. The treatment group received 6 mg intramuscular dexamethasone every 12 hours for a total of 4 doses or until delivery. Primary outcome was the rate of neonatal RD. Secondary neonatal outcomes included the need for respiratory support, neonatal intensive care unit (NICU) admission, hypoglycemia, necrotizing enterocolitis, intraventricular hemorrhage, and neonatal death. Statistical analyses were performed by using SPSS software.ResultsThe rate of RD in LPI was significantly lower in the treatment group than in the matched control group (10.3% vs. 23.1%, respectively), with relative risk [RR] 0.44; 95% confidence interval [CI] 0.21 – 0.96 and p = 0.03. Neonatal hypoglycemia was more common in the dexamethasone group than in the matched group (25.6% vs. 12.8%, respectively; RR, 2.00; 95% CI, 1.00 – 3.99; p = 0.04). There were no significant between-group differences in the incidence of respiratory support, NICU admission or length of hospital stay.ConclusionsAdministration of antenatal dexamethasone to women at risk for late preterm birth could significantly reduce the rate of respiratory distress in late preterm infants.