From the Guidelines
Betamethasone is the recommended steroid for preterm babies to reduce respiratory distress syndrome. The standard regimen consists of two 12mg intramuscular injections given 24 hours apart to the mother before delivery, ideally between 24 and 34 weeks of gestation, with optimal benefit occurring when administered 24 hours to 7 days before birth 1. Alternatively, dexamethasone can be used at 6mg intramuscularly every 12 hours for four doses. These antenatal corticosteroids work by accelerating fetal lung maturation, specifically increasing surfactant production, which reduces surface tension in the alveoli and prevents their collapse during exhalation.
This treatment significantly reduces the incidence of respiratory distress syndrome by approximately 40%, decreases neonatal mortality, and lowers the risk of intraventricular hemorrhage 1. For maximum effectiveness, the full course should be completed, though even partial courses offer some benefit. In cases where delivery is still imminent after 7 days from the initial course and before 34 weeks, a rescue course may be considered.
Some key points to consider:
- Antenatal steroids significantly reduce mortality, respiratory distress syndrome, and surfactant use in preterm infants, most consistently in those born between 28 and 34 weeks’ gestation 1.
- The combination of antenatal steroids and postnatal surfactant replacement independently and additively reduces mortality, the severity of respiratory distress syndrome, and air leaks in preterm infants 1.
- Antenatal steroids may reduce the need for prophylactic and early rescue surfactant replacement in infants born after 27 to 28 weeks’ gestation, although this has not been proven in large randomized controlled trials 1.
Overall, the use of antenatal corticosteroids, such as betamethasone, is a crucial step in reducing the incidence and severity of respiratory distress syndrome in preterm infants, ultimately improving morbidity, mortality, and quality of life outcomes.
From the Research
Steroid Recommendations for Preterm Babies
To reduce respiratory distress syndrome in preterm babies, the following steroids are recommended:
- Betamethasone: Antenatal administration of 24 milligrams of betamethasone has been associated with a significant reduction in mortality, respiratory distress syndrome, and intraventricular haemorrhage in preterm infants 2.
- Dexamethasone: Administration of 24 milligrams of dexamethasone has also been shown to reduce the incidence of respiratory distress syndrome and neonatal mortality 2, 3.
- Hydrocortisone: Two grams of hydrocortisone has been associated with a significant reduction in mortality, respiratory distress syndrome, and intraventricular haemorrhage in preterm infants 2.
Benefits of Antenatal Corticosteroids
The benefits of antenatal corticosteroids for preterm babies include:
- Reduced incidence of respiratory distress syndrome 2, 4, 5, 3
- Reduced neonatal mortality 2, 5, 3
- Reduced incidence of intraventricular haemorrhage 2
- Reduced severity of respiratory distress syndrome 4, 6
Additive Effects with Surfactant Supplementation
Antenatal corticosteroids have been shown to have additive effects with surfactant supplementation in reducing the incidence and severity of respiratory distress syndrome 4, 6.