Low and high birth weight linked to cerebral palsy: possible liability implications: study shifts focus from intrapartum events.

Babies born at either extreme of weight for gestational age--low or high--are at increased risk for cerebral palsy, according to a 10-country European study of 4,503 children.

That low birth weight is associated with cerebral palsy (CP) and other untoward outcomes is widely recognized, but the finding that high birth weight also carries risk was unexpected and supports the concept that CP may be the result of abnormal intrauterine growth rather than intrapartum asphyxia.

"This is an interesting study," Dr. Mark Evans, director of the Institute for Genetics and Fetal Medicine, St. Luke's-Roosevelt Hospital Center, New York, said in an interview.

"It is certainly very consistent with the more modern explanation of the etiology of cerebral palsy, which is that the outcome is either an intrinsic function of underlying risk within the fetus or it results from increased susceptibility to external stimuli such as infections, rather than the commonly touted litigation approach of believing it is because of intrapartum events," said Dr. Evans, who was not involved in the study.

"Ultimately, I believe this study will help lessen some of the liability problems faced by obstetricians because it provides further data that, in the vast majority of cases, cerebral palsy is not related to intrapartum events," he said.

The study included 4,503 singleton children with CP born between 1976 and 1990.

Among affected babies born between 32 and 42 weeks' gestation, those whose weight fell below the 10th percentile were four to six times more likely to have CP than were those whose weights were in the 25th-75th percentile, the investigators found. Those whose weight was above the 97th percentile also were at elevated risk, though less so than the very-low-birth-weight subjects. The heaviest babies' risk ranged from 1.6 to 3.1 (Lancet 362[9390]:1106-11, 2003).