Two new meta-analyses cast doubt on link between acetaminophen and autism, other NDDs

While some researchers have reported a possible association between prenatal exposure to acetaminophen (Tylenol/ paracetamol) and autism, two separate multinational research groups have detected no clear link.

In the first study, Jameela Sheikh and colleagues conducted an “umbrella” review of nine reviews, including a total of 40 observational studies, that explored acetaminophen use during pregnancy and children’s odds of developing autism spectrum disorders (ASD) or attention-deficit/hyperactivity disorder (ADHD). Four of the reviews they examined included meta-analyses of multiple studies.

The researchers say, “The reviews reported a possible to strong association between maternal paracetamol intake and autism or ADHD or both in offspring.” However, they say, “Seven of the nine reviews advised caution when interpreting the findings owing to the potential risk of bias and confounding in the included studies.” They add that confidence in the quality of the reviews (based on AMSTAR 2, which measures the quality of studies) was “low to critically low.”

In two studies that adjusted for familial factors, the researchers say, the association between ASD or ADHD disappeared when sibling-controlled analyses were performed. The researchers say, “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.”

They conclude, “Existing evidence does not clearly link maternal paracetamol use during pregnancy with autism or ADHD in offspring.”

In the second paper, Anick Bérard and colleagues reviewed 16 studies exploring prenatal acetaminophen exposure and the odds of neurodevelopmental disorders (NDDs) in children. They report, “Acetaminophen use during pregnancy was not associated with a statistically significant increased risk of ASD when considering physician-based diagnoses.” While they detected a modest increase in ADHD in children exposed to acetaminophen in utero, they say this was most likely due to inherent study biases and underlying genetic factors. No clear association was seen between prenatal acetaminophen exposure and other NDDs.

Emphasizing that most current studies exhibit significant methodological weaknesses, both research groups call for carefully designed studies that account for factors such as familial and genetic influences, the reasons for acetaminophen use, and the duration, dosage, and timing of use.

See related ARRI position statement

Citations

“Maternal paracetamol (acetaminophen) use during pregnancy and risk of autism spectrum disorder and attention deficit/hyperactivity disorder in offspring: umbrella review of systematic reviews,” Jameela Sheikh, John Allotey, Soha Sobhy, Maria Nieves Plana, Hilario MartinezBarros, Harshitha Naidu, Fatima Junaid, Reecha Sofat, Ben W. Mol, Louise C. Kenny, Melissa Gladstone, Helena Teede, Javier Zamora, and Shakila Thangaratinam, British Medical Journal, November 2025. Address: Shakila Thangaratinam, [email protected].

—and—

“Tylenol during pregnancy: No strong evidence ties use to autism or ADHD risk,” news release, British Medical Journal, November 6, 2025.

—and—

“Systematic review and meta-analysis: acetaminophen use during pregnancy and the risk of neurodevelopmental disorders in childhood,” Anick Bérard, Judith Cottin, Lisiane F. Leal, Cyndie Picot, Justine Pleau, Jan M. Friedman, Per Damkier, Michel Cucherat, Sura Alwan, Lucie Jurek, Louise M. Winn, Bruce C. Carleton, Andréa D. Bertoldi, Sonia M. Grandi, Reem Masarwa, Philippe Dodin, Michael Ceulemans, Robert W. Platt, Mikail Nourredine, Erika Björkström Gram, Areti Angeliki Veroniki, Jérôme Massardier, and Andrea C. Tricco, Journal of the American Academy of Child & Adolescent Psychiatry, November 2025 (free online). Address: Anick Bérard, 3175 Chem. de la Côte-SainteCatherine, Montréal, QC H3T 1C5, Canada, anick.berard@umontreal.

—and—

“Review finds no link between acetaminophen use in pregnancy and neurodevelopmental disorders,” news release, Elsevier, November 9, 2025.