Prenatal steroid treatment protects the brains of premature babies against hemorrhages, reducing by half the risk of severe hemorrhaging and the possible development of related neurologic problems such as cerebral palsy, researchers at Stanford University School of Medicine reported.
Their study, “Impact of antenatal steroids on intraventricular hemorrhage in very-low-birth weight infants,” was published in the Journal of Perinatology.
The National Institutes of Health (NIH) currently recommends that mothers at risk of giving birth during weeks 24 to 34 of pregnancy should take steroids (normal pregnancy is about 40 weeks). Steroid treatments were originally developed for maturation of fetal lungs prior to an early birth, but recent evidence suggests that steroids also protect the brains of premature infants after their birth.
Knowledge about steroid treatment in the context of modern neonatal care is limited, as is its effect on extremely premature babies, as steroids were only being used to treat babies born at 26 weeks of pregnancy or later.
Researchers analyzed data, collected from the California Perinatal Quality Care Collaborative, from 25,979 infants born between 2007 and 2013. These infants were delivered during weeks 22 and 32 of pregnancy and weighed less than 3.3 pounds (1.5 kilograms) at birth. Specifically, the scientists evaluated the effect of steroids on intraventricular hemorrhage, characterized by bleeding in the space around the brain where cerebrospinal fluid circulates.
Intraventricular hemorrhage is associated with an increased risk of death and, in case of survival, with the development of neurological problems such as cerebral palsy, hydrocephalus, and mental retardation.
Among the infants studied, 87 percent were born to mothers treated with steroids prior to giving birth. In these babies, the risk of all types of intraventricular hemorrhage was one-third lower, when compared to babies born to untreated mothers. Moreover, the risk of the most severe forms of intraventricular hemorrhage was reduced by about 50 percent. The association between steroid use and decreased intraventricular hemorrhage risk was significant in babies born between 22 and 29 weeks of pregnancy, but not in those born at or after 30 weeks.
Importantly, the study showed for the first time that steroid treatment was beneficial for extremely premature babies, or those born between 22 and 24 weeks of gestation.
“We speculate that steroids may accelerate the maturation of blood vessels in the brain and make them stronger. That may make the baby less vulnerable to rapid shifts in blood pressure, which could otherwise cause bleeding similar to a stroke,” Dr. Henry Lee, the study’s senior author, in a university news release. “It’s helpful to know that prenatal steroids are an impactful component to our strategy to prevent these potentially devastating hemorrhages.”