Major Review Finds No Link Between Maternal Tylenol and Autism Spectrum Disorder, ADHD

A comprehensive review of 40 studies and 9 systematic reviews found no link between maternal acetaminophen (Tylenol; Kenvue) and autism or attention deficit/hyperactivity disorder (ADHD).

In early September 2025, the FDA and Department of Health and Human Services announced label changes to Tylenol in response to supposed evidence suggesting that using acetaminophen during pregnancy may be associated with a heightened risk of neurological conditions.²

They cited multiple studies that have emerged in recent years—studies that do find an increased risk of ASD, ADHD, or neurodevelopmental disorders with maternal acetaminophen use. However, these studies have methodological pitfalls, such as smaller sample sizes, lack of control for confounding factors, or self-reported data, lending to their unreliability.¹

In response to the announcement made by the US health agencies, researchers from the University of Liverpool in England performed an umbrella analysis of all existing literature investigating maternal acetaminophen and the risk of ASD or ADHD. A total of 9 reviews encompassing 40 studies were included—6 studies on autism and 17 on ADHD. Four of these reviews conducted meta-analyses.²

“Existing systematic reviews on prenatal exposure to paracetamol and risk of autism and ADHD in offspring included heterogeneous studies, and many suggested a positive association,” wrote the authors. “But few reviews accounted for the study quality, appropriate control of relevant confounders, and rigorous ascertainment of drug use and outcomes in the primary studies when interpreting the evidence.”²

The overlap among primary studies across reviews was substantial, with a corrected covered area of 23%. Overall, the reviews reported a possible to strong association between maternal paracetamol use and the risk of autism or ADHD, or both, in children.

However, 7 of the 9 reviews cautioned against overinterpretation of these findings, citing potential bias and confounding factors within the included studies. Based on the AMSTAR 2 (A MeaSurement Tool to Assess Systematic Reviews) criteria, confidence in the findings was rated as low for 2 reviews and critically low for 7.²

Only 1 review included studies (n = 2) that appropriately adjusted for familial factors and unmeasured confounding through sibling-controlled analyses. In these studies, the increased risks observed in whole-cohort analyses—autism (HR 1.05, 95% CI 1.02–1.08) and ADHD (HR 1.07, 95% CI 1.05–1.10; HR 2.02, 95% CI 1.17–3.25)—did not persist in the sibling-controlled analyses (autism [HR 0.98, 95% CI 0.93–1.04] and ADHD [HR 0.98, 95% CI 0.94–1.02; HR 1.06, 95% CI 0.51–2.05]).²

“In the primary studies that appropriately adjusted for familial factors through a sibling-controlled design and for key time-varying maternal characteristics and indications for paracetamol use, the observed association between exposure to paracetamol and risk of autism and ADHD in childhood disappeared or attenuated,” the authors wrote.²

“This disappearance of association in the sibling analyses, previously observed in the whole cohort, suggests that shared family factors, such as parental mental health, genetic predisposition, and socioenvironmental background, explain much of the observed risk.”²

The author’s findings help to further establish the safety of maternal acetaminophen use but also highlight a critical nuance: that the underlying reasons for using acetaminophen themselves contribute to the observed associations with neurodevelopmental outcomes, rather than the medication alone.

REFERENCES

1. Halpern L. FDA alleges association between prenatal acetaminophen use and autism in children. Pharmacy Times. September 23, 2025. Accessed November 10, 2025. https://www.pharmacytimes.com/view/fda-alleges-association-between-prenatal-acetaminophen-use-and-autism-in-children

2. Sheikh J, Allotey J, Sobhy S, et al. Maternal paracetamol (acetaminophen) use during pregnancy and risk of autism spectrum disorder and attention deficit/hyperactivity disorder in offspring: umbrella review of systematic reviews. BMJ. November 10, 2025. Doi:10.1136/bmj-2025-088141