Sixteen-year-olds who weighed less than 2,000 grams (about 4.5 pounds) at birth and are not disabled are still more likely than the average teenager to have physical and mental difficulties, according to a report in the October issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.
Low birth weight is known to increase the risk for major disabilities such as cerebral palsy and mental retardation, but researchers now suspect that low birth weight may also contribute to minor difficulties in motor skills and in thinking, learning and memory (cognitive abilities). These problems may last into adolescence, according to background information in the article.
Agnes H. Whitaker, M.D., Columbia University and New York State Psychiatric Institute, New York, and colleagues studied 474 non-disabled adolescents who were born at or admitted to one of three New Jersey hospitals between 1984 and 1987 and weighed less than 2,000 grams at birth. The participants, who had an average age of 16 at the time of assessment for this study, underwent intelligence and motor tests in their homes.
Compared with the standardization sample, or the large group of teens used to provide a reference point for the assessments, the adolescents with low birth weight had more motor problems. Their IQ scores were within the normal range, but on average were significantly lower than the average for their age group. Those who were male, who had injuries to the white matter (nerve tissue) of the brain on neonatal ultrasound and who spent more days on a ventilator as an infant were more likely to have motor difficulties. Social disadvantages, a lower fetal growth ratio (calculated by dividing birth weight by the median weight for the infant's age) and white matter injury also predicted lower IQ scores.
"The finding that, independent of social risk, specific prenatal, perinatal and neonatal biological risk factors are associa
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Contact: Elizabeth Streich
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JAMA and Archives Journals
2-Oct-2006