Birth weight problems linger

Children born underweight but not disabled are still more likely to have physical and mental problems as teenagers, researchers have found.

Lower scores on tests of intelligence, memory, learning and motor skills were more likely among 16-year-olds who weighed less than 4.4 pounds at birth but were otherwise free of disabilities, the study said.

Low birth weight is a known risk factor for mental retardation and cerebral palsy, but subtler brain injuries inflicted by an undersized head may afflict others born underweight, especially boys, it said.

IQ scores of the children born underweight, while within the average range for their age group, tended to be 4 to 7 points lower than the norm, the study published in the October issue of Archives of Pediatrics & Adolescent Medicine said.