Acetaminophen, widely known by the brand name Tylenol, has long been considered a safe and accessible option for managing pain and fever during pregnancy. For decades, physicians have recommended it as a first-line treatment, especially when alternatives such as ibuprofen and aspirin carry known risks to fetal development. However, emerging research has raised serious concerns about the neurodevelopmental impact of prenatal acetaminophen exposure. A growing body of evidence suggests that children exposed to acetaminophen in utero may face a significantly increased risk—up to three times higher—of developing autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD).
This article reviews the latest scientific findings, evaluates the strength of the evidence, and explores the legal implications for families affected by prenatal Tylenol exposure. At The Law Office of Melinda J. Helbock, A.P.C., we monitor pharmaceutical safety trends to support survivor families and pursue justice in cases of medical harm.
Scientific Evidence Linking Acetaminophen to Neurodevelopmental Disorders
In August 2025, researchers from the Harvard T.H. Chan School of Public Health and the Icahn School of Medicine at Mount Sinai published a comprehensive systematic review analyzing 46 studies involving more than 100,000 participants. Using the Navigation Guide Systematic Review methodology—a rigorous framework for evaluating environmental health risks—the authors concluded that prenatal acetaminophen exposure was associated with increased incidence of neurodevelopmental disorders, including ASD and ADHD. The review emphasized that while acetaminophen remains important for treating maternal fever and pain, its use should be limited to the lowest effective dose for the shortest duration, and only under medical supervision (Harvard T.H. Chan School of Public Health, 2025).
Dr. Andrea Baccarelli, senior author of the study, noted that even a modest increase in risk could have major public health implications given the widespread use of acetaminophen during pregnancy. The study’s findings were echoed by Dr. Diddier Prada of Mount Sinai, who emphasized that higher-quality studies consistently showed a link between acetaminophen use and neurodevelopmental disorders (USA Today, 2025).
Another major study published in JAMA in April 2024 analyzed data from 2.48 million children in Sweden. The researchers found that children exposed to acetaminophen during pregnancy had a 0.09% higher absolute risk of autism and a 0.19% higher risk of ADHD compared to unexposed children. While these absolute differences may appear small, the relative risk was significantly elevated in certain subgroups, particularly those with prolonged or frequent exposure (Ahlqvist et al., 2024).
Understanding Association vs. Causation
Despite the consistency across multiple studies, the scientific community remains divided on whether acetaminophen causes neurodevelopmental disorders or is merely associated with them. Critics argue that observational studies cannot definitively establish causation due to potential confounding factors. For example, maternal fever, infection, stress, and genetic predisposition may contribute to neurodevelopmental outcomes independently of acetaminophen use.
The American College of Obstetricians and Gynecologists (ACOG) continues to recommend acetaminophen as a safe option for managing pain and fever during pregnancy, citing the risks of untreated maternal illness. According to Dr. Christopher Zahn, ACOG’s chief of clinical practice, “Pregnant patients should not be frightened away from the many benefits of acetaminophen, which is safe and one of the few options pregnant people have for pain relief” (PBS NewsHour, 2025).
Nonetheless, the Harvard and Mount Sinai review emphasized that the consistency of findings across high-quality studies warrants precautionary measures. The authors recommended individualized risk-benefit assessments and called for updated clinical guidelines to reflect the emerging evidence.
Legal Implications and Ongoing Litigation
The growing concern over acetaminophen’s neurodevelopmental risks has triggered a wave of litigation. In 2022, hundreds of tylenol lawsuits were filed against manufacturers and retailers of Tylenol, alleging failure to warn consumers about the potential risks of prenatal exposure. These cases were consolidated into Multidistrict Litigation (MDL 3043) in the Southern District of New York.
However, in late 2023, the federal judge overseeing the MDL excluded key expert testimony linking acetaminophen to autism and ADHD, citing insufficient scientific reliability. This decision dealt a major blow to plaintiffs and led to the dismissal of the MDL. Appeals are currently underway, and some law firms are pursuing state-level claims independently.
The legal strategy in these cases hinges on demonstrating that manufacturers had access to scientific evidence suggesting a link between acetaminophen and neurodevelopmental disorders but failed to provide adequate warnings. Plaintiffs argue that had they been informed of the risks, they would have sought alternative treatments or used acetaminophen more cautiously.
If future litigation succeeds, settlement amounts could vary widely based on the severity of the child’s condition, medical expenses, emotional distress, and lost earning potential. The outcome may also depend on the strength of scientific evidence and the ability to establish causation in court.
Public Health Messaging and Regulatory Response
The controversy surrounding acetaminophen has prompted renewed scrutiny of public health messaging. In September 2025, the Trump administration announced plans to advise pregnant women to limit Tylenol use to high fevers only, citing concerns about autism risk. Health Secretary Robert F. Kennedy Jr. stated that the administration would publish a report examining environmental factors contributing to rising autism rates, including acetaminophen use and folate deficiency (MSN News, 2025).
While the report has not yet been released, the announcement marks the first time a U.S. administration has publicly linked acetaminophen to autism risk. Public health experts have expressed concern about the potential for confusion and misinformation, emphasizing the need for balanced, evidence-based guidance.
The Food and Drug Administration (FDA) has not issued new warnings about acetaminophen use during pregnancy but continues to monitor the scientific literature. The agency advises pregnant women to consult their healthcare providers before using any medication and to avoid nonsteroidal anti-inflammatory drugs (NSAIDs) after 20 weeks of gestation due to known risks.
Recommendations for Expectant Mothers
Given the conflicting evidence and ongoing debate, expectant mothers should take a cautious and informed approach to acetaminophen use. Key recommendations include:
- Consult a healthcare provider before using any medication during pregnancy.
- Use the lowest effective dose for the shortest duration necessary.
- Avoid frequent or prolonged use unless medically indicated.
- Monitor symptoms and seek early intervention if developmental concerns arise in the child.
Healthcare providers should discuss the potential risks and benefits of acetaminophen use with pregnant patients and document informed consent when recommending treatment.
Conclusion
The emerging evidence linking Tylenol use in pregnancy to increased risk of autism and ADHD is both compelling and complex. While causation remains debated, the consistency across high-quality studies warrants caution, transparency, and legal accountability. As litigation evolves and public health policies adapt, families deserve clear information and access to justice.
At The Law Office of Melinda J. Helbock, A.P.C., we advocate for informed consent, rigorous science, and survivor-centered legal support. If you or a loved one has been affected by prenatal acetaminophen exposure, contact us for a confidential case review and strategic guidance.
References
- Ahlqvist, V. H., Sjöqvist, H., Dalman, C., Karlsson, H., Stephansson, O., Johansson, S., Magnusson, C., Gardner, R. M., & Lee, B. K. (2024). Acetaminophen use during pregnancy and children’s risk of autism, ADHD, and intellectual disability. JAMA, 331(14), 1205–1214. https://doi.org/10.1001/jama.2024.3172
- Harvard T.H. Chan School of Public Health. (2025, August 14). Using acetaminophen during pregnancy may increase children’s autism and ADHD risk. https://hsph.harvard.edu/news/using-acetaminophen-during-pregnancy-may-increase-childrens-autism-and-adhd-risk/
- USA Today. (2025, August 22). Tylenol in pregnancy linked to autism. Why is science contradictory? https://www.usatoday.com/story/life/health-wellness/2025/08/22/acetaminophen-tylenol-pregancy-autism-adhd/85779424007/
- PBS NewsHour. (2025, September 17). Research doesn’t show using Tylenol during pregnancy causes autism. https://www.pbs.org/newshour/health/research-doesnt-show-using-tylenol-during-pregnancy-causes-autism-here-are-5-things-to-know
- MSN News. (2025, September 22). Trump administration to link Tylenol use during pregnancy to autism: What research says. https://www.msn.com/en-in/health/health-news/trump-administration-to-link-tylenol-use-during-pregnancy-to-autism-what-research-says/ar-AA1N1MeH
