June 6, 2003
MEDIA CONTACT: Karen Blum
Prematurity, Infections Most Likely Causes of Brain Damage Among Infants
The most likely causes of brain damage among low birthweight infants are prematurity and infections, not oxygen starvation, a Johns Hopkins study has found.
Studying 213 babies born weighing less than 3 pounds, 5 ounces, the researchers noted that the smaller the infants were at birth and the less time they spent in the womb, the more likely they were to have some form of brain damage. Babies born with infections were more likely than those without infections to have brain complications. The report is published in the June issue of the journal Obstetrics & Gynecology.
"A lot of medical malpractice cases try to relate brain damage to oxygen deficiency during the birthing process," says lead author Cynthia J. Holcroft, M.D., an instructor of gynecology and obstetrics. "In our study, oxygen deficiency played a very small role in the neurologic injuries seen in these infants. Even with the increase in the Caesarian rate from 5 percent to almost 25 percent, and the widespread introduction of electronic fetal heart rate monitoring, the incidence of cerebral palsy and other problems has remained unchanged over the past 40 years."
Researchers followed all babies born at Johns Hopkins between April 1999 and December 2001 weighing less than 3 pounds, 5 ounces and who were admitted to the hospital's neonatal intensive care unit. To compare those born with brain disorders such as seizures or bleeding, and those born without such complications, they reviewed all maternal and neonatal records, checking gestational age at delivery, mode of delivery, birth weights, Apgar scores (measure of newborns' development and health) and infection, among other factors.
Seventy-seven (36 percent) of the infants studied had some type of neurologic problem. Of those, 61 had bleeding, eight had seizures, 13 had hydrocephalus (an abnormal increase in cerebrospinal fluid) and nine had periventricular leukomalacia (brain softening). Several infants had more than one complication. Moreover, only three of 52 newborns whose umbilical cord gasses were measured had evidence of acidity, a finding that argues against the birthing process as the cause of neurological problems.
There were seven deaths among the newborns, in six infants with brain damage and one baby without. All of these babies had more serious disease including herpes simplex virus II, pneumonia and pulmonary hypoplasia (underdevelopment of the lungs) or were born prematurely.
Co-authors were Karin J. Blakemore, M.D.; Marilee Allen, M.D.; and Ernest M. Graham, M.D.
Holcroft, CJ et al, "Prematurity and Neonatal Infection are Most Predictive of Neurologic Morbidity in Very Low Birthweight Infants," Obstetrics & Gynecology, June 2003, Vol. 101, No. 6, pages 1249-1254.
Related Web sites:
Women's Health Services at Johns Hopkins
Obstetrics & Gynecology