Researchers at the University of Pennsylvania School of Nursing have discovered a link between low birth weight and children diagnosed with autism.
Indeed, premature infants are apparently five times more likely to have autism than children born at a normal weight.
The children, some born as small as about a pound, and all followed for 21 years, were born from September 1984 through July 1987 in Middlesex, Monmouth, and Ocean counties in New Jersey at birth weights from 500 to 2000 grams or a maximum of about 4.4 pounds.
"As survival of the smallest and most immature babies improves, impaired survivors represent an increasing public health challenge," explained lead author Jennifer Pinto-Martin, director of the Center for Autism and Developmental Disabilities Research and Epidemiology at Penn Nursing.
"Emerging studies suggest that low birth weight may be a risk factor for autism spectrum disorders."
As Pinto-Martin notes, links between low birth weight and a wide range of motor and cognitive problems have been well established for some time, but this is the first study that specifically establishes that the children are also at increased risk for autism spectrum disorders, or ASD.
"Cognitive problems in these children may mask underlying autism," she said. "If there is suspicion of autism or a positive screening test for ASD, parents should seek an evaluation for an ASD. Early intervention improves long-term outcome and can help these children both at school and at home."
Future studies at Penn will investigate possible links between brain hemorrhage, a complication of premature birth and autism by examining brain ultrasounds taken of the children as newborns.