A new umbrella review published in The BMJ concludes that acetaminophen (the active ingredient in Tylenol) taken during pregnancy is not clearly linked to autism or ADHD in children. The analysis examined nine systematic reviews that together included 40 primary studies from the past decade. Although some primary studies reported associations between maternal acetaminophen use and neurodevelopmental outcomes, the umbrella review found those studies to be of low to critically low confidence and to suffer from important methodological flaws.
Key concerns cited by the reviewers include failure to adjust for familial and genetic factors, maternal health and indication for acetaminophen use, and other potential unmeasured confounders. The authors noted that studies not accounting for these influences cannot accurately estimate the effect of in utero acetaminophen exposure on child neurodevelopment. They also found no established biological mechanism linking acetaminophen exposure in pregnancy to autism or ADHD.
Independent experts praised the review’s methodology. Dimitrios Siassakos, a professor of obstetrics and gynecology at University College London, said the evidence for a link is tenuous and that reported associations are likely confounded by factors shared within families. Sherry Ross, an OB-GYN at Providence Saint John’s Health Center, said the review confirms there is no association and warned that exaggerated claims have caused unnecessary worry for pregnant people.
Clinical context and safety guidance
Obstetricians and clinical guidance continue to consider acetaminophen the safest option for treating pain and reducing fever during pregnancy. Fever itself carries risks in pregnancy, including increased risk of neural tube defects, so treating high fever is important. G. Thomas Ruiz, an OB-GYN at MemorialCare Orange Coast Medical Center, noted that acetaminophen does not cross the placenta in a way that other pain relievers, such as ibuprofen, do, and that many other analgesics are not recommended in pregnancy.
Experts emphasize that untreated pain and fever can be harmful to both mother and fetus, and that the potential harms of avoiding acetaminophen when it’s needed likely outweigh the unsupported risks suggested in some reports.
Public debate and regulatory responses
The review comes after public statements from U.S. political leaders and federal agencies suggesting a possible association between maternal Tylenol use and autism. In September, President Trump and HHS officials drew attention to studies suggesting a link; the FDA later announced it would consider label changes noting a potential association. HHS Secretary Robert Kennedy Jr. has since softened his stance, saying evidence is not sufficient to show acetaminophen definitively causes autism but advising cautious use.
Tylenol’s manufacturer has stated that rigorous research does not show acetaminophen causes autism. Legal and political actions have followed: a Texas attorney general filed a lawsuit against Johnson & Johnson alleging insufficient warnings about pregnancy use.
Epidemiology and causes of autism and ADHD
CDC data indicate about 3% of U.S. children are diagnosed with autism by age 8 (with higher prevalence in boys) and roughly 11% of children ages 3 to 17 have been diagnosed with ADHD. Autism and ADHD are complex conditions with likely multiple contributing factors. Known or suspected risk factors for autism include family history, specific genetic mutations, advanced parental age, low birth weight, and exposure to certain environmental toxins. ADHD also has recognized genetic and environmental contributors; prenatal smoking and alcohol exposure have been implicated.
Prior studies using sibling-control designs and other methods have suggested that associations observed in less-adjusted models may be attributable to confounding. A 2024 JAMA study using sibling controls found no association between prenatal acetaminophen use and risk of autism, ADHD, or intellectual disability, supporting the view that familial factors explain many previously reported links.
What this means for pregnant people
Current evidence does not establish a causal link between acetaminophen use during pregnancy and autism or ADHD. Acetaminophen remains the recommended analgesic for pregnancy when needed, especially to treat high fever. Clinicians and patients should use the lowest effective dose for the shortest necessary time, informed by clinical indication and individual circumstances. As with all medications in pregnancy, discuss persistent symptoms or concerns with a healthcare provider to weigh benefits and risks.
