Rare Pregnancy Infections Linked to Threefold Higher Autism Risk in Children: Study - Video

Children born with rare infections acquired before birth were about three times more likely to be diagnosed with autism and more than seven times more likely to have intellectual disability, according to a large Swedish study published in JAMA Pediatrics.

Researchers from Karolinska Institutet studied TORCH infections, a group of infections that can sometimes pass from a pregnant woman to the developing fetus. These include cytomegalovirus, rubella, toxoplasma and herpesvirus.

The study analysed health and education records of 3.7 million people born in Sweden between 1987 and 2021. Among them, 975 had been diagnosed with a congenital TORCH infection. Participants were followed for up to 30 years.

Children with a congenital TORCH infection had about three times the risk of later autism compared with those without an infection. Their risk of intellectual disability was more than seven times higher. For severe to profound intellectual disability, the increase was as high as 30-fold.

Despite these large relative increases, congenital TORCH infections were rare and accounted for only a small proportion of cases across the population. Researchers estimated that they were associated with about 1.2% of severe intellectual disability cases in Sweden and around 0.034% of autism cases.

The researchers also compared affected children with their siblings who did not have a congenital TORCH infection. The association remained similar, suggesting that shared family factors alone were unlikely to explain the findings.

No clear association was found between congenital TORCH infections and conditions such as ADHD or obsessive-compulsive disorder. However, children with these infections had lower average school grades, even when they did not have autism or intellectual disability.

The findings suggest that certain infections acquired before birth may affect brain development over the long term. Researchers highlighted prevention as an important public health measure, noting that some congenital infections, including rubella, can be prevented through vaccination.

REFERENCE: Hugo Sjöqvist, Christina Dalman, David Mataix-Cols, Reneé M. Gardner, Håkan Karlsson. Congenital TORCH Infections and Neurodevelopmental Outcomes. JAMA Pediatrics, 2026; DOI: 10.1001/jamapediatrics.2026.4229