A new review published in The BMJ reports no clear evidence that paracetamol use during pregnancy increases the risk of autism or attention-deficit/hyperactivity disorder (ADHD) in children. Researchers found that earlier studies suggesting a link were generally based on low-quality evidence and may reflect shared genetic or environmental factors within families rather than a causal effect.
Paracetamol remains widely recommended by regulatory agencies as the safest over-the-counter option for managing fever and pain during pregnancy.
Review Evaluated Evidence Quality
The umbrella review assessed studies published through September 30, 2025, using data from Embase, Medline, Cochrane, and PsycINFO. Two independent reviewers screened all articles, with a third resolving disagreements. Researchers extracted information on study design, outcomes, confounders, risk of bias, and effect estimates. Input from individuals with lived experience of autism and ADHD was also included.
The analysis covered 40 primary studies summarized in nine systematic reviews, including four meta-analyses. Most primary studies were prospective cohorts; only two were case-control studies. Autism outcomes were evaluated in six studies and ADHD in 17.
Significant Weaknesses Across Studies
Investigators reported broad methodological limitations in the existing evidence base. Common issues included unregistered protocols, incomplete search strategies, and failure to list excluded studies. While many reviews described small positive associations between prenatal paracetamol exposure and neurodevelopmental outcomes, seven of nine reviews cautioned that these findings should not be interpreted as causal, citing uncontrolled confounders and bias.
Sibling Analyses Show No Association
Meta-analysis estimates for ADHD risk ranged from 1.2 to 1.4, with smaller positive estimates for autism. However, these associations disappeared when researchers used sibling-comparison models that account for shared genetic and environmental factors.
In one study, the hazard ratio for ADHD dropped from 1.07 to 0.98 when comparing exposed children with their unexposed siblings. For autism, the estimate decreased from 1.05 to 0.98. These findings suggest that familial influences—not paracetamol exposure—likely explain previously reported associations.
Researchers concluded that current evidence is insufficient to link paracetamol use during pregnancy to autism or ADHD, and emphasized the need for high-quality studies that better control for familial and unmeasured confounding.
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