Newborn Brain Injuries Stem From Infections, Not Delivery

White matter, the tracts of nerve fibers that communicate messages in the brain, is generally injured at so-called "end zones" between the long, penetrating arteries that supply blood to the brain. These zones are susceptible to the type of fall in cerebral blood flow and oxygen that could occur during complications in delivery, as marked by excess acid in the umbilical cord.

The Hopkins team reviewed medical records of 150 premature babies who had white matter injuries and were born between May 1994 and September 2001. They compared each baby's delivery to that of the next healthy baby delivered at the same gestational age (23-24 weeks), looking for causes of problems.

The researchers found that acid levels in the umbilical cords were similar in both brain-injured and healthy babies, as were many other factors such as maternal infections and the percentage born by Caesarean versus vaginal delivery. The only difference noted was that brain-injured babies were more likely to have evidence of infections of the cerebrospinal fluid, blood and windpipe.

"Our study refutes the fact that white matter injuries are caused by delivery," says Ernest Graham, M.D., senior study author and assistant professor of gynecology/obstetrics. "The biggest association with these injuries in our study was clearly neonatal infections."

Graham says while you can treat the infections after birth, it's hard to know when they originated. Also, even if the infections are treated, the babies could still be at higher risk for permanent brain damage.