THURSDAY, Jan. 12 (HealthDay News) -- School-age children exposed to HIV before birth are at increased risk for language problems and could benefit from early diagnosis and classroom intervention, according to a new study.

Researchers looked at 468 children, ages 7 to 16, born to mothers with HIV infection during pregnancy. Of those children, 306 were HIV-infected and 162 did not have HIV, the virus that causes AIDS.

Overall, 35 percent of the children had difficulty understanding spoken words and expressing themselves verbally, said the researchers at the U.S. National Institutes of Health and other institutions.

On a series of language ability tests, the average score of the children exposed to HIV before birth was in the lowest 21 percent of all children who have taken the test.

All the children exposed to HIV before birth tended to have language delays, regardless of whether they later become infected with HIV, the researchers said.

"Our results show that children exposed to HIV have more than twice the chance of having a language impairment than do children in the general population," Dr. George Siberry, of the Pediatric, Adolescent and Maternal AIDS Branch of the U.S. National Institute of Child Health and Human Development, said in an NIH news release.

The researchers weren't able to determine if the high rates of language problems in HIV-exposed children are actually due to HIV exposure or are caused by other factors, such as family status, mothers' substance use, environment, or social or economic background.

The study recently appeared in the Journal of Developmental and Behavioral Pediatrics.

Routine screening for language impairment might benefit children exposed to HIV before birth, even if they don't have any obvious signs of language problems, the researchers suggested.

More information

The U.S. National Dissemination Center for Children with Disabilities has more about speech and language impairments.