Efficacy of a Single Dose of Antenatal Steroid in Surfactant-treated Babies Under 31 Weeks’ Gestation

Abstract

Antenatal steroid therapy can lessen morbidity from respiratory distress syndrome in preterm infants. Two doses 24 hours apart generally are recommended, starting 1-7 days before delivery. Experience with women who present in preterm labor and can receive only 1 dose shows that their infants do as well as those given what is thought to be optimal 2-dose treatment. This retrospective study evaluated single-dose treatment in 226 infants less than 31 weeks' gestation whose mothers received surfactant (Survanta®, Exosuif®, or Curosurf®) prophylactically. Eighty-nine of them (group 1) received no steroid antenatally; 68 (group 2) received a single dose 4-24 hours before delivery; and 69 (group 3) were given 2 or more doses 1-7 days before delivery. Each dose consisted of 12 mg betamethasone, injected intramuscularly. The groups were well matched for birth weight, gestational age, gender, and multiple births. Timing of the first dose of surfactant also was similar in all groups. Group 2 and group 3 infants had significantly higher 1-minute Apgar scores than those not given steroid. CRIB scores, a clinical risk index, were 47% lower in group 2 than in group 1 infants, and 38% lower in group 3. Scores did not differ significantly between groups 2 and 3. There were no significant group differences in the duration of ventilation or oxygen dependence. Compared to untreated infants, severe intraventricular hemorrhage was reduced 23% in group 2 and 22% in group 3, again with no significant difference between these groups. Mortality was 31.5% in the untreated group, 8.6% in the single-dose group, and 7.4% when 2 or more steroid doses were given. A single antenatal dose of steroid, given 4-24 hours before delivery of a surfactant-treated preterm infant, is as effective as 2 or more doses.