Congenital Infections Linked to Increased Risk of Autism and Intellectual Disabilities
A new study has identified a link between infections transmitted to the fetus during pregnancy and an increased risk of a subsequent diagnosis of autism or intellectual disability.
The study included 3.7 million people born in Sweden between 1987 and 2021. Of these, 975 participants were diagnosed with a congenital TORCH infection. Participants were followed for up to three decades, allowing researchers to assess the potential link between such infections and the children's subsequent development and educational outcomes.
Increased risk of developmental disorders
According to the study results, children who had a congenital TORCH infection faced an approximately threefold higher risk of a subsequent autism diagnosis and a more than sevenfold higher risk of an intellectual disability diagnosis compared to children without such an infection.
The most significant difference was observed regarding severe and profound intellectual disability, where the risk was up to 30 times higher.
However, researchers note that congenital TORCH infections remain rare and account for only a small fraction of all autism cases in the general population. The authors estimate that approximately one in five children born with such an infection may subsequently be diagnosed with autism.
What are TORCH infections?
TORCH is a collective term for a group of infections that can be transmitted from a pregnant woman to the fetus, such as syphilis, rubella, toxoplasmosis, cytomegalovirus, and herpesvirus.
Some of these pathogens can cross the placental barrier and directly affect the fetus. Such infections can increase the risk of miscarriage, stillbirth, and other pregnancy complications.
Impact on School Performance
Researchers have identified a link between congenital infections and not only subsequent medical diagnoses but also educational outcomes.
Specifically, among 420 individuals diagnosed with a TORCH infection, poorer academic performance was observed—even in cases where they were not subsequently diagnosed with autism or intellectual disability.
Cytomegalovirus (CMV) infection is the most common of the aforementioned infections worldwide. According to data cited in the publication, it affects approximately one in 150 newborns, with higher prevalence rates in low- and middle-income countries.
The Importance of Prevention
The study’s authors emphasize the need to strengthen preventive measures, particularly in regions with high rates of infectious diseases.
Particular attention is paid to vaccination and other measures designed to prevent infections that can be transmitted from a pregnant woman to the fetus.
The researchers also note that existing healthcare systems may fail to detect some asymptomatic cases. In particular, newborn screening for TORCH infections is not universally implemented. According to the authors, improving early detection mechanisms could facilitate more effective management of the risks associated with such infections.
