Studies indicating a potential link
- A 2020 JAMA Psychiatry study found that babies with higher levels of acetaminophen in their umbilical cord blood at birth had a higher likelihood of an autism diagnosis later in childhood.
- A 2019 National Institutes of Health (NIH)-funded study, also published in JAMA Psychiatry, found that children with the highest level of acetaminophen in their cord blood had 3.62 times the risk of an autism spectrum disorder (ASD) diagnosis compared to those with the lowest levels.
- A 2018 meta-analysis of over 132,000 mother-child pairs suggested that prolonged acetaminophen exposure during pregnancy could increase the risk of autism.
- A 2025 review led by researchers at Mount Sinai found evidence to support an association between prenatal acetaminophen exposure and neurodevelopmental disorders, though they recommended caution and further study.
Studies showing no causal link
- A large 2024 study funded by the NIH and published in JAMA analyzed data from over 2 million children in Sweden. By comparing siblings with different prenatal acetaminophen exposure, researchers controlled for shared genetics and environment. This study found no increased risk of autism, ADHD, or intellectual disability associated with acetaminophen use during pregnancy.
- A 2025 fact-check by Al Jazeera, citing multiple experts and the large 2024 study, concluded that no credible scientific evidence proves Tylenol causes autism.
