The risk of premature birth presents significant challenges for newborns, with underdeveloped lungs being one of the most serious complications. When a delivery is anticipated early, medical teams often turn to a specific treatment to help prepare the baby’s body for life outside the womb. This intervention is designed to accelerate the maturity of the fetal organ system most vulnerable to early delivery. The treatment is administered to the pregnant person, allowing the medication to cross the placenta and begin working before birth occurs. It is an effective method used globally to mitigate the severe respiratory issues associated with prematurity.
Defining Antenatal Corticosteroids
The medical intervention known as the “steroid shot” is a course of medication belonging to the drug class called antenatal corticosteroids. These synthetic hormones are chemically similar to natural stress hormones produced by the body. The two primary medications used are Betamethasone and Dexamethasone, both highly effective at crossing the placental barrier to reach the fetus. The purpose of this treatment is to prevent or significantly reduce the severity of Neonatal Respiratory Distress Syndrome (RDS). RDS is a condition where a newborn’s immature lungs cannot sustain normal oxygen exchange, which is a leading cause of illness and death in premature infants.
How the Treatment Develops Fetal Lungs
Corticosteroids accelerate the maturation of the fetal lungs by directly influencing specific cells within the air sacs, or alveoli. The medication crosses the placenta and stimulates Type II pneumocytes, which are the cells responsible for producing pulmonary surfactant. Surfactant is a complex mix of lipoproteins that coats the inner surface of the alveoli. This specialized coating lowers the surface tension inside the lungs, preventing the tiny air sacs from collapsing entirely when the baby exhales.
Without sufficient surfactant, the alveoli stick together, requiring the newborn to expend an immense amount of energy with every breath to re-inflate them. The steroid treatment rapidly increases the production and release of surfactant, effectively “oiling” the inner surfaces of the lungs. The corticosteroids also promote structural maturation by inducing changes in the lung tissue itself. This accelerated development improves the lung’s mechanical function and enhances its ability to clear fluid after birth, preparing the airways for air breathing.
When and How the Shot is Given
The decision to administer antenatal corticosteroids depends on the gestational age and the risk of imminent preterm delivery. The treatment is typically recommended for individuals at risk of giving birth between 24 and 34 weeks of gestation, although it may be considered up to 36 weeks and six days in specific high-risk circumstances. The medication is given via intramuscular injection, usually into the mother’s thigh or arm muscle.
Treatment Protocols
There are two common protocols for a full course of treatment, depending on the drug chosen. The Betamethasone regimen consists of two 12-milligram doses administered 24 hours apart. Alternatively, the Dexamethasone regimen involves four 6-milligram doses, each given 12 hours apart. For the treatment to provide the greatest benefit, the baby should be born at least 24 hours after the first injection and within seven days of the full course.
Safety Considerations for Mother and Baby
A single course of antenatal corticosteroids is regarded as safe, with the short-term benefits to the baby’s lung health outweighing the risks in threatened preterm delivery. For the mother, common, temporary side effects include soreness at the injection site and a feeling of flushing or warmth. The treatment can also temporarily elevate blood sugar levels, especially in women with pre-existing or gestational diabetes. Close monitoring of glucose is implemented during and immediately following the administration of the shots.
In the fetus, the medication can lead to a transient decrease in movement and heart rate variability, which resolves within 24 to 48 hours. After birth, newborns exposed to the steroids have an increased risk of developing low blood sugar, known as hypoglycemia. Hospital staff implement specific monitoring protocols to manage the newborn’s glucose levels immediately after delivery.