NEW YORK (Reuters Health) – Many 12-year-olds who were delivered preterm at very low birthweight have lower IQs and more developmental problems than similarly aged children born at term, a team reports in the March issue of Pediatrics.

Dr. Betty R. Vohr of Brown University in Providence, Rhode Island, and colleagues compared cognitive, language, behavioral, and educational outcomes of 375 children with birth weights between 600 and 1250 grams born between 1989 and 1992 with 111 age-matched full-term controls.

The preterm cohort had a full-scale IQ of 88, a verbal IQ of 91 and a performance IQ of 87. These children had psychometric test scores averaging 6-14 points lower than controls.

On the Clinical Evaluation of Language Fundamentals, a test of basic language skills, 22%-24% of preterm children scored in the abnormal range compared with 2%-4% of controls.

Three-quarters (76%) of the preterm children who had perinatal brain injury due to intraventricular hemorrhage required school support services, compared with 44% of preterm children without brain injury and 16% of controls

Preterm children exhibited more behavior problems than their full-term counterparts, the investigators found.

Severe neonatal brain injury was the strongest predictor of low intelligence. Factors associated with better cognition were use of antenatal steroids, higher maternal education, and a two-parent family. Minority status was associated with greater deficits.

“Although our findings pertain to a group of children born more than 15 years ago, trends over time suggest that the gap in neuropsychological skills between preterm and term children has remained relatively constant,” Dr. Vohr and colleagues note.

They conclude, “These findings indicate that extended efforts to prevent serious brain injury in preterm infants are needed.”

Pediatrics 2009;123:1037-1044.