Despite widespread belief among doctors and lay people that cerebral palsy results from lack of oxygen to the baby's brain during labor and delivery, a new report says that birth asphyxia alone accounts for 10 percent of cases at most.
The study found that the vast majority of children who develop cerebral palsy experience prenatal problems, including maternal infections, clotting disorders and strokes, that damage the developing brain long before labor begins.
The findings were described yesterday at a news conference in Albany, N.Y., held by the New York division of the American College of Obstetricians and Gynecologists, which has been concerned about the growing unwillingness of doctors to practice obstetrics because of litigation risks, skyrocketing jury awards and soaring rates for malpractice insurance.
The findings, based on hundreds of scientific studies, were compiled by an expert panel convened by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics. The report represents the first time in this country that all the variables and studies were analyzed in one place, and it "clearly shows that there isn't one cause of cerebral palsy," said David Clark, a neonatologist at Albany Medical College.
The report, reviewed by 100 independent experts, was endorsed by a wide range of organizations, including the March of Dimes Birth Defects Foundation, the National Institute of Child Health and Human Development, and the Centers for Disease Control and Prevention.
Cerebral palsy is a relatively rare movement disorder that typically becomes apparent by the child's second or third year and affects about half a million Americans. There are several forms of cerebral palsy, all of which involve uncontrollable movements and posture. Only one form, spasticity involving all four limbs, is related to lack of oxygen to the brain during birth.
Babies who develop cerebral palsy typically have symptoms at birth of neonatal encephalopathy, characterized by poor muscle tone and reflexes, difficulty waking, breathing problems or seizures. Neonatal encephalopathy may or may not result in permanent brain damage.
Data summarized in the report were developed since the 1980s and are well known to many experts in maternal and fetal medicine, perinatology and pediatric neurology. But the report's authors said the true causes of cerebral palsy have yet to be recognized by most doctors, parents and lawyers.
Findings published in a pediatric journal in the 1980s from the government-sponsored Collaborative Perinatal Project revealed that only a fraction of cases of cerebral palsy - probably less than 10 percent - could be traced to an oxygen shortage at birth and that no cause was apparent in the majority of cases. The findings were not well publicized at the time.
In the decades since, new techniques, including sonograms, CT scans, MRIs and fetal monitoring, have revealed a host of other explanations for brain-injured babies, mainly damage that occurs during pregnancy, long before labor begins.