From the Guidelines
Yes, antenatal steroids significantly increase fetal lung development, as demonstrated by a decrease in the composite outcome of need for respiratory support and severe respiratory morbidity in preterm infants 1. The recommended regimen is betamethasone 12 mg intramuscularly given twice, 24 hours apart, to pregnant women at risk of preterm delivery between 34 and 36 weeks of gestation, as supported by the American Journal of Obstetrics and Gynecology study 1. This treatment has been shown to reduce the incidence of respiratory distress syndrome and mortality in preterm infants, with benefits beginning within 24 hours of the first dose and lasting for at least 7 days 1. Key benefits of antenatal steroids include:
- Reduction in need for respiratory support in preterm infants
- Decrease in severe respiratory morbidity
- Acceleration of surfactant production, enhancing lung structural maturation and improving pulmonary function
- Minimal side effects for a single course, with the exception of potential transient hyperglycemia in women with diabetes. It is essential to note that antenatal steroids provide the most significant benefits when administered to pregnant women at risk of preterm delivery between 34 and 36 weeks of gestation, as indicated by the study published in the American Journal of Obstetrics and Gynecology 1.
From the Research
Effects of Antenatal Steroids on Neonatal Lung Development
- Antenatal corticosteroids have been shown to reduce the risk of respiratory distress syndrome (RDS) in preterm infants 2, 3, 4, 5.
- The administration of antenatal corticosteroids accelerates fetal lung maturation, reducing the incidence of RDS and leading to improved neonatal outcomes 2, 3, 6, 5.
- A single course of antenatal corticosteroids is effective in preventing RDS and neonatal mortality, with benefits extending to a broad range of gestational ages 2, 3.
- The use of antenatal corticosteroids also reduces the risk of perinatal death, neonatal death, and intraventricular hemorrhage (IVH) 3, 4.
Mechanism of Action
- Antenatal corticosteroids stimulate the production of surfactant phospholipids by alveolar type II cells, enhance the expression of surfactant-associated proteins, and reduce microvascular permeability 6.
- The administration of antenatal corticosteroids accelerates overall structural maturation of the lungs, leading to improved lung function in preterm infants 6.
Recommendations for Use
- A single course of antenatal corticosteroids is recommended for women at risk of preterm birth, with benefits seen regardless of resource setting (high, middle, or low) 3.
- Betamethasone and dexamethasone are the most widely used corticosteroids, with similar effectiveness and a recommended dosage of 24mg in divided doses over a 24-hour period 5.
- The use of repeated courses of corticosteroids may be considered in specific cases, but concerns have been raised regarding long-term outcomes beyond 34 gestational weeks 5.