Rare infections during pregnancy linked to higher risk of autism in children

TIRANA / ATA – Rare infections that can be transmitted from mother to fetus during pregnancy are linked to a higher risk of autism and intellectual disabilities in children, according to a new study by researchers at the Karolinska Institute in Sweden, published in the scientific journal “JAMA Pediatrics”.

The study analyzed data from about 3.7 million people born in Sweden between 1987 and 2021, of whom 975 had a congenital TORCH infection, and participants were followed for up to three decades.

TORCH is a group of infections that in rare cases can pass from a pregnant woman to the fetus.

The group includes, among others, cytomegalovirus (CMV), rubella, toxoplasmosis and herpes viruses.

These infections can cross the placenta and directly infect the fetus.

According to the results, children born with a congenital TORCH infection were about three times more likely to later be diagnosed with autism, compared to children who had not had this infection.

The risk of being diagnosed with an intellectual disability was more than seven times higher, while for severe to very severe forms of this condition the risk was up to 30 times higher.

The researchers stress that, despite the large increase in relative risk, the impact of these infections on the overall number of autism cases is limited, since congenital TORCH infections are rare.

By their estimate, these infections may explain about 0.034% of autism cases in Sweden and about 1.2% of severe intellectual disability cases.

The researchers also estimate that about one in five children born with a TORCH infection may later develop autism.

To examine whether the observed links could be explained by shared family factors, the researchers also compared children with TORCH infection to their siblings who had not had the infection.

Similar results in this analysis supported the observed link.

The study found no clear links between TORCH infections and several other neuropsychiatric disorders, such as ADHD or obsessive-compulsive disorder.

However, an impact on school results was noted — even children without an autism or intellectual disability diagnosis had, on average, lower school results compared to peers without infection.

The researchers stress that the results show a statistical link and do not imply that TORCH infection directly causes autism in every case.

They also note that some of these infections can be prevented, emphasizing the importance of preventive measures and vaccination, particularly against rubella.

The study, titled “Congenital TORCH infections and neurodevelopmental outcomes: A population-based and sibling study”, was published on September 21, 2026 in “JAMA Pediatrics”.

The research was funded by the Swedish Research Council.