Swedish study links TORCH infections to autism and intellectual disability risks

A large-scale study conducted by researchers at the Karolinska Institutet in Sweden has identified a significant link between TORCH infections during pregnancy and increased risks of neurodevelopmental conditions in children.

Analyzing data from approximately 3.7 million individuals born in Sweden between 1987 and 2021, the research published in JAMA Pediatrics found that children exposed to TORCH infections—a group including cytomegalovirus (CMV), rubella, toxoplasmosis, and herpes viruses—faced a 3.1-fold higher risk of being diagnosed with autism spectrum disorder (ASD). The risk for intellectual disabilities was even more pronounced, appearing 7.22 times more likely, with the risk for severe forms of the condition increasing up to 30 times.

To account for shared familial and genetic factors, researchers compared affected children with their unaffected siblings. The association remained significant in these comparisons. While the relative risk is high, researchers noted that because TORCH infections are rare, their impact on the total number of autism cases in the general population remains small, accounting for approximately 0.034% of cases in the studied cohort.