A broad review published in The BMJ found no clear evidence that acetaminophen (the active ingredient in Tylenol) taken during pregnancy causes autism or ADHD in children. The umbrella review pooled and assessed nine systematic reviews that together examined 40 primary studies from the past decade. While some individual studies reported associations between maternal acetaminophen use and neurodevelopmental outcomes, the reviewers judged those studies to be of low to critically low confidence and identified important methodological weaknesses.
Major limitations identified include inadequate adjustment for familial and genetic factors, failure to account for the mother’s underlying health or the reason acetaminophen was used, and other unmeasured confounders. The authors concluded that studies that do not control for these influences cannot reliably estimate the effect of prenatal acetaminophen exposure on child neurodevelopment. The review also found no established biological mechanism linking routine acetaminophen use in pregnancy to autism or ADHD.
Independent experts praised the review’s methods. Several clinicians noted that reported links are likely confounded by factors shared within families and that the evidence for a causal relationship is weak. Others warned that overstating a connection has caused unnecessary anxiety for pregnant people.
Clinical context and safety guidance
Obstetricians and clinical guidelines continue to regard acetaminophen as the safest option for treating pain and reducing fever during pregnancy. Fever itself is a risk factor in pregnancy and can increase the chance of some birth defects, so treating high fever is important. Some alternative pain relievers are not recommended in pregnancy, and experts emphasize that untreated pain or fever can be harmful to both the pregnant person and the fetus. The review’s findings support current advice to use the lowest effective acetaminophen dose for the shortest necessary duration, and to seek medical guidance for persistent symptoms.
Public debate and regulatory responses
The review appears amid public and regulatory attention to studies suggesting a possible association. Earlier statements from political leaders and federal agencies drew attention to those studies; the FDA said it would consider whether label changes were warranted. Some officials later characterized the evidence as insufficient to prove a causal link but advised cautious use. The manufacturer of Tylenol has stated that rigorous research does not show acetaminophen causes autism. Legal and political actions have followed in some jurisdictions, including a lawsuit alleging inadequate warnings about pregnancy use.
Epidemiology and causes of autism and ADHD
CDC surveillance estimates that 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. Both conditions are complex and likely arise from multiple interacting genetic and environmental factors. Known or suspected risk factors include family history and specific genetic mutations, advanced parental age, low birth weight, and exposure to certain environmental toxins. Prenatal smoking and alcohol exposure have been implicated in ADHD risk.
More rigorous study designs, including sibling-control analyses, have suggested that associations seen in less-adjusted studies may be explained by familial confounding. A 2024 JAMA study using sibling controls reported no association between prenatal acetaminophen use and autism, ADHD, or intellectual disability, supporting the view that shared family factors account for many previously reported links.
What this means for pregnant people
Current evidence does not establish that acetaminophen use in pregnancy causes autism or ADHD. Acetaminophen remains the recommended analgesic for pregnant people when treatment is needed—particularly to manage high fever. Patients and clinicians should discuss symptoms, use the lowest effective dose for the shortest appropriate time, and weigh benefits and risks based on individual circumstances. If concerns persist, talk with a healthcare provider to determine the best approach.
