When premature birth is anticipated, a “steroid shot” is often given to the pregnant individual. This treatment helps the baby’s lungs mature more quickly, significantly improving outcomes after an early arrival. It is a standard part of care for pregnancies at risk of preterm delivery.
Understanding Antenatal Corticosteroids
Antenatal corticosteroids are synthetic hormones, like betamethasone and dexamethasone, given to pregnant individuals at risk of premature delivery. Their core function is to accelerate fetal lung maturation. This aims to prevent or reduce the severity of Respiratory Distress Syndrome (RDS), a serious breathing condition common in preterm infants.
RDS occurs because preterm babies’ lungs often lack sufficient surfactant. Without it, the tiny air sacs (alveoli) can collapse, making breathing difficult. Corticosteroids promote lung maturity, ensuring the baby’s lungs are better equipped to function outside the womb. This intervention is given when preterm delivery is likely, typically before 37 weeks of gestation.
How the Shot Aids Fetal Lung Development
Antenatal corticosteroids enhance fetal lung development by targeting Type II pneumocytes. They stimulate these cells to increase the production of surfactant phospholipids and associated proteins. This increased surfactant reduces surface tension within the alveoli, preventing collapse during exhalation and aiding breathing after birth.
Beyond surfactant production, these medications promote structural maturation of the fetal lungs. They influence cell maturation, enhance phospholipid synthesis, and regulate pulmonary fluid metabolism. Corticosteroids also stimulate antioxidant enzymes within the fetal lung, preparing it for air breathing. These combined effects ensure the lung tissue is more compliant and efficient at gas exchange.
Administering the Treatment
Antenatal corticosteroids are administered to pregnant individuals at risk of preterm delivery, between 24 and 34 weeks of gestation. In some situations, they may be considered as early as 22 weeks or up to 36 weeks. The treatment is recommended when preterm birth is likely within the next seven days.
The common dosage regimen involves intramuscular injections. For betamethasone, a typical course consists of two doses of 12 mg each, given 24 hours apart. Alternatively, dexamethasone can be administered as four doses of 6 mg each, given 12 hours apart. Medical guidelines suggest that even if delivery is imminent and only one dose can be given, there can still be some benefit.
Outcomes and Important Considerations
Antenatal corticosteroids substantially reduce the incidence and severity of Respiratory Distress Syndrome and decrease the risk of neonatal death. The treatment also lowers the likelihood of other serious complications associated with prematurity, such as intraventricular hemorrhage (bleeding in the brain) and necrotizing enterocolitis (a severe bowel condition).
For the pregnant individual, temporary blood sugar changes may occur, especially with diabetes, requiring close monitoring. Studies have explored potential longer-term considerations for the baby, such as lower birth weight or neurodevelopmental outcomes. However, the benefits of preventing severe respiratory issues and improving survival rates in preterm infants outweigh these considerations.