Evaluation of the effect of antenatal betamethasone on neonatal respiratory morbidities in late preterm deliveries (34-37 weeks).

Since late preterm neonates (34-36 weeks) are more at risk of respiratory morbidities, the present study was conducted to evaluate the effect of antenatal betamethasone on neonatal respiratory morbidities in women with late preterm delivery. This randomized clinical trial was performed on 240 women with single pregnancy that was at high risk of late preterm delivery (34-37 weeks). The patients were randomly assigned to either betamethasone (intramuscular injection of 12 mg of betamethasone in two doses with an interval of 24 hours) or the control group. The two groups were compared with each other in terms of respiratory morbidities, NICU admission and its cause and duration, hospitalization in the neonatal ward for more than 6 hours, and the duration of hospitalization. Of all, 79 neonates (33%) had one or more respiratory morbidities. The observed morbidities in the betamethasone group were significantly less prevalent than those in the control group (19 neonates (16%) and 60 neonates (50%), respectively,  < .001). The most frequently observed respiratory morbidity was needed for oxygen for more than an hour (34 infants, 14%). The need for oxygen for more than an hour, the need for continuous positive airway pressure (CPAP), respiratory distress syndrome (RDS), and the need for surfactant were significantly less observed in betamethasone group than in the control group. A total of 43 neonates (18%) were admitted to NICU and then hospitalized in the neonatal ward; the number of admitted neonates were significantly lower in the betamethasone group than in the control group (11 neonates (9%) and 32 neonates (27%), respectively,  < .001). Moreover, 15 neonates (6%) were admitted to the neonatal ward and there were no significant differences between the betamethasone and control groups (10 neonates (8%) and 5 neonates (4%), respectively,  = .182). Totally, 58 neonates (24%) were hospitalized; the number of hospitalized neonates was significantly lower in the betamethasone group than in the control group (21 neonates (18%) and 37 neonates (31%), respectively,  = .016). The results of this study showed that the antenatal administration of betamethasone in late preterm delivery (34-37 weeks) can improve respiratory morbidities and decrease the frequency of NICU admission.