No Evidence that Paracetamol Increases Autism Risk, Says Analysis of Robust Studies

Paracetamol is an over-the-counter drug, commonly taken for treating symptoms such as body aches and fever. In September 2025, the US administration issued a health guidance, pointing to "mounting evidence finding a connection between acetaminophen (paracetamol) use during pregnancy and autism."

However, previous research suggesting a small link between paracetamol in pregnancy and an increased risk of autism and ADHD were often prone to biases, researchers from the University of Liverpool, UK and institutes in Europe said.

The team reviewed evidence from 43 studies and looked for those with the largest, most rigorous methodologies, such as analyses involving sibling comparisons.

"Current evidence does not indicate a clinically important increase in the likelihood of autism spectrum disorder, ADHD, or intellectual disability in children of pregnant individuals who use paracetamol as directed, supporting existing recommendations on its safety," the authors wrote.

"When considering sibling comparison studies, paracetamol exposure during pregnancy was not associated with the risk of autism spectrum disorder," they said.

The findings suggest that previously reported associations between paracetamol in pregnancy and risk of a neurodevelopmental disorder could be due to maternal factors, including an underlying pain, discomfort, fever or a genetic predisposition, rather than a direct effect from paracetamol, the researchers said.

Rudrarup Bhattacharjee, a postdoctoral researcher from The University of Adelaide in Australia and not involved with the study, said the findings are significant because "earlier concerns were largely driven by conventional observational studies that could not fully separate the effects of paracetamol from the underlying reasons it was taken for, for example maternal fever, pain, or infection -- factors that themselves can influence pregnancy and childbirth outcomes."

"By carefully addressing these sources of bias, the study clarifies that previously reported links are unlikely to be causal," Bhattacharjee said.

Researchers, including those from the London School of Hygiene and Tropical Medicine and not involved in the study, said in a commentary article, published in The Lancet Obstetrics, Gynaecology and Women's Health journal, "This study reinforces that the strongest epidemiological evidence does not support a link between paracetamol use during pregnancy and neurodevelopmental harm, confirming that, when clinically-indicated, paracetamol remains an important and evidence-supported option for the management of fever and pain during pregnancy, particularly in settings where untreated maternal infection and fever pose well-established risks to fetal survival and neurodevelopment."