Betamethasone dosing interval at 12 or 24 h apart: A systematic review and meta-analysis

To compare the effectiveness of administering 24 mg of betamethasone in two doses (12 mg each) at 12-hour versus 24-hour intervals in patients at risk of preterm delivery.

A search was conducted in Ovid, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, CINAHL, Scopus, and Google Scholar up to February 22, 2023. Search terms included "Betamethasone," "Preterm delivery," "Respiratory distress," "Dosing interval," and related keywords. No language or geographic restrictions were applied.

Randomized controlled trials of pregnant women at risk for preterm delivery between 23 and 34 weeks of gestation, randomized to receive 24 mg of betamethasone in two doses, either 12 or 24 h apart.

The primary outcome was the incidence of respiratory distress syndrome, with secondary outcomes including adverse maternal and neonatal events. Summary measures were reported as relative risk with 95% confidence intervals.

Two randomized controlled trials (429 patients) were included. The rate of RDS was lower in the 12-hour dosing group (34.3 % vs. 45.7 %; RR 0.76, 95 % CI 0.46-1.25), but the difference was not statistically significant. Significant reductions in NICU admissions, surfactant use, and an increase in birthweight were observed in the 12-hour group. No significant differences were found for perinatal mortality, neonatal sepsis, necrotizing enterocolitis, intraventricular hemorrhage, retinopathy of prematurity, chorioamnionitis, or maternal fever > 100°F.

The 12-hour betamethasone dosing regimen showed benefits in reducing NICU admissions and surfactant use. Further studies are needed to confirm its advantages for other outcomes.