Single versus multiple courses of antenatal betamethasone and neonatal outcome: a randomized controlled trial.

OBJECTIVES This study compared the beneficial and adverse neonatal effects of a single versus repeated courses of antenatal betamethasone. SETTING Tertiary care hospital DESIGN Open labeled, randomized controlled trial. PARTICIPANTS Pregnant women (26-33 weeks) at risk of preterm delivery, who received one course of antenatal betamethasone and remained undelivered for 7 days. Those with uncertain gestation, major malformations and frank chorioamnionitis were excluded. INTERVENTIONS Subjects were randomized to receive weekly antenatal betamethasone until 34 weeks or no further betamethasone. OUTCOME MEASURES Primary: incidence of severe respiratory distress syndrome (RDS). Secondary: incidence of non-severe RDS and other neonatal morbidity; birth weight, length and occipito-frontal circumference (OFC); and, development and growth at 6 mo corrected age. RESULTS 38 subjects were allocated to each group. Severe RDS was similar in multiple and single course groups (7% vs. 3% respectively, P=0.34), as was incidence of other morbidity. Composite outcome of RDS and or death within 28 days tended to be less in multiple course group (P=0.07). Birth anthropometry was similar in the 2 groups. At 6 mo corrected age (n=44), weight and length were significantly lower in multiple course group (p=0.003 and P=0.007, respectively), whereas OFC was not different (P=0.1). There were no differences vis a vis neurodevelopmental outcomes. CONCLUSIONS A single course of antenatal betamethasone was as efficacious as multiple courses, with respect to prevention of neonatal morbidity. Multiple antenatal betamethasone courses have long-term adverse effects on infant weight and length growth, but not on OFC and neurodevelopment.