Preemies between 28 and 32 weeks are not harmed by a treatment no longer used to help their lungs mature before birth, according to findings of a study in this month's Pediatrics. Even though previous observational studies suggested that repeated courses of steroids in the womb may result in brain damage, this study shows that the babies' brains are virtually unaffected.
"The consensus in recent years has been to no longer give women in preterm labor more than one course of steroids because of possible adverse effects, but it means more babies are born needing ventilation," said Sanjiv Amin, M.D., assistant professor of Pediatrics at the University of Rochester Medical Center and author of the study. "These findings may give us back a tool to help give these fragile babies a better chance of survival."
Before concerns arose in 2000 about safety of multiple courses of steroids, many mothers in on-and-off preterm labor received several rounds before delivering. Now, when mothers go into preterm labor, obstetricians will often administer only a single course of steroids to help strengthen the baby's lungs upon birth. But if the birth is successfully held off for more than seven days, the mother does not receive another course of medication and the baby's lungs may not be protected.
This is regrettable, because one of the biggest challenges for babies born preterm is breathing on their own. Many develop respiratory distress syndrome because their lungs have not developed a protective film over their air sacks, called surfactant, which aids in the transfer of oxygen and decreases the work of breathing. Because of that, they may receive medications and supplemental oxygen, which can cause problems of their own. Some infants develop bronchopulmonary dysplasia, a scarring and inflammation of the lungs, from the oxygen treatment. Others can begin to leak air through the lungs and into the body cavity. Any of these complications, especially coupled with an infection, can be life-threatening.
Previous studies showed neurological complications from multiple courses of dexamethasone, a steroid prepared with sulfur. However, clinicians do not commonly use that steroid anymore and have largely switched to sulfur-free steroids, such as betamethasone. This study was based on infants who received betamethasone prior to birth, and they did not show the same adverse effects as previous studies.