Newborns’ brain injury caused by an infection

Risk managers facing claims of newborn brain injury have more support for what the physicians have probably been saying all along: The tragic outcome wasn’t caused by anything that happened in your facility.

The research could have a major impact on how medical malpractice cases involving brain injury are pursued, says Ernest Graham, MD, assistant professor of gynecology/obstetrics at the Johns Hopkins Medical Institutions in Baltimore. Medical malpractice cases frequently try to link injuries to the white matter of a newborn’s brain — a precursor to cerebral palsy and other disorders — to the baby’s delivery, but Graham says his research indicates that such injuries are more closely associated with neonatal infections.

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, Graham explains. 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.

Few injuries related to birth

Healthcare Risk Management obtained a copy of the study Graham will soon publish in a medical journal. It shows that 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 cesarean vs. 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," Graham says. "The biggest association with these injuries in our study was clearly neonatal infections."

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

"There’s a general perception that obstetric intrapartum risk factors are responsible for most cases of brain injury in babies and there is more and evidence out there that refutes that," he says. "I think it’s very conclusive when you use umbilical cord gasses to try to find out if the baby’s hypoxic during delivery."

In the brain-injured patients Graham studied, fewer than 6% had evidence of severe hypoxia or metabolic acidosis in their cord gasses, and he says that shows that "intrapartum factors are not responsible for the majority of these cases."

The new research reinforces the claims in a recent report from the American College of Obstetricians and Gynecologists in Washington, DC. That report released in 2003, Neonatal Encephalopathy and Cerebral Palsy: Defining the Pathogenesis and Pathophysiology, suggested that the vast majority of neonatal encephalopathy and cerebral palsy originate from developmental or metabolic abnormalities, autoimmune and coagulation defects, infection, trauma, or combinations of these factors.

The ACOG report was endorsed by six organizations including the National Institute of Child Health and Human Development of the National Institutes of Health in Washington and the Centers for Disease Control and Prevention in Atlanta.

The report indicated that hypoxia during labor or delivery is not a significant cause in most of the cases of neonatal encephalopathy or cerebral palsy, with less than one-quarter of infants with neonatal encephalopathy having any evidence of hypoxia during labor. An underlying event before labor was the primary factor for the adverse outcome in 70% of neonatal encephalopathy cases and contributory in another 25%, the report said.

Collect blood gases at birth

Graham says the arterial umbilical cord gasses can be key to determining the true cause of brain injuries in newborns, and therefore they can be crucial to defending yourself against a malpractice claim. If you don’t collect them at birth, it may be too late by the time you’re facing a malpractice lawsuit.

Some hospitals routinely collect cord gasses on all babies, while others have a policy of collecting gasses whenever the baby appears depressed or abnormal.

The policy may call for collecting the samples and then waiting to see if there is any concern about the baby. You don’t necessarily have to test every sample you collect, but routine testing is a solid risk reduction strategy, Graham says.

"The cord gasses help rule out intrapartum factors in a lot of cases," he says. "The long-term benefit of proving that a baby had normal cord gas at delivery can outweigh the cost of doing more cord gasses."