New York, New York (AHN)-Investigators with the Women and Infants Transmission Study Group report that early diagnosis of an AIDS-defining illness in children, who acquired HIV infection from their mothers, is associated with impaired cognitive development.

According to the study's investigators, children with a diagnosis of AIDS "scored significantly lower in all domains of cognitive development, across all time points" than those with HIV infection but without AIDS, or children exposed to but not infected with HIV.

Lead investigator Dr. Renee Smith, of the University of Illinois at Chicago, tells Reuters that it is not completely clear why the AIDS-defining episodes so strongly affect the cognitive abilities in these children.

However, Smith speculates that children who develop AIDS very early in life "may have been infected with the virus during earlier periods of their mother's pregnancy, rather than later, during the birthing process."

Smith suggests, in the report featured in the medical journal Pediatrics, "Being infected during pregnancy may mean either that the baby was infected for a longer period of time, or that the virus and its pathological processes were introduced at a time when critical brain development was occurring, resulting in a long-term impact on functioning."