Congenital TORCH Infections Linked to Intellectual Disability and Autism

Congenital TORCH infections were associated with substantially increased risks of intellectual disability and autism, with associations persisting after accounting for shared familial factors, according to a nationwide cohort study published in JAMA Pediatrics.

TORCH infections—toxoplasmosis, syphilis, rubella, cytomegalovirus (CMV), or herpes simplex—are established causes of severe fetal injury, but their population-level contribution to neurodevelopmental and psychiatric outcomes, independent of familial confounding, had not been quantified. Investigators used Swedish national health, birth, insurance, education, and death registers, incorporating sibling comparisons to help address confounding by shared family factors.

Among 3,666,002 individuals born in Sweden between 1987 and 2021, including 975 with a diagnosed congenital TORCH infection, exposure was associated with increased risk of intellectual disability (adjusted hazard ratio [HR], 7.22; 95% CI, 6.14-8.49) and autism (adjusted HR, 3.10; 95% CI, 2.55-3.76), with similar or greater HRs in sibling comparisons (intellectual disability: HR, 11.28; 95% CI, 5.97-21.33; autism: HR, 3.19; 95% CI, 1.97-5.15).

Risk rose with intellectual disability severity, from an adjusted HR of 3.01 for mild disability to 23.51 for severe to profound disability, and was higher for autism with co-occurring intellectual disability (HR, 6.23) than without (HR, 1.97). Exposed individuals also had lower school grades in adolescence, even without diagnosed autism or intellectual disability (decrease of 1.50 points; 95% CI for the decrease, 0.40-2.60 points). No consistent association was observed with obsessive-compulsive disorder, and an initial attention-deficit/hyperactivity disorder association disappeared after sibling adjustment. The authors noted TORCH infections were rare (2.5 per 10,000 births) and accounted for only a small proportion of cases at the population level despite the large relative risks. A key limitation: the study was restricted to clinically diagnosed, symptomatic infections, since Sweden does not implement newborn TORCH screening.

The authors concluded these findings support preventive strategies, particularly for CMV, and underscore the value of vaccination programs against vertically transmitted infections such as rubella.

Source: Sjöqvist H, Dalman C, Mataix-Cols D, Gardner RM, Karlsson H. Congenital TORCH infections and neurodevelopmental outcomes. JAMA Pediatr. Published online September 21, 2026. doi:10.1001/jamapediatrics.2026.4229