Researchers analyzed the quality, validity, and biases in existing evidence linking maternal paracetamol (acetaminophen) use during pregnancy with the risk of attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children.
Study
The study systematically evaluated the strength and validity of available evidence. Researchers searched major databases, including Embase, Medline, the Cochrane Database of Systematic Reviews, PsycINFO, Epistemonikos, and grey literature sources, to identify systematic reviews and meta-analyses on maternal paracetamol use and child neurodevelopmental outcomes.
Eligible reviews included cohort, cross-sectional, case-control studies, or randomized trials examining prenatal exposure and risk of ADHD or ASD. Titles and abstracts were screened, followed by full-text evaluation. The quality of the review was assessed using the AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews 2) framework.
From 663 identified records, nine systematic reviews encompassing 40 primary studies met the inclusion criteria, including four meta-analyses. Most reviews were published within the past decade and focused on maternal use throughout pregnancy. Only one examined both antenatal and postnatal exposure.
The quality evaluation revealed significant methodological deficiencies. Most reviews lacked registered protocols, comprehensive search strategies, and justifications for study exclusions. Risk of bias assessments were either incomplete or missing, and none utilized standardized tools such as the ROBINS-I or ROBINS-E. Statistical methods were often inadequate, with only one review pooling adjusted estimates. As a result, overall confidence was rated low in two reviews and critically low in seven.
Results
All reviews reported positive associations between prenatal paracetamol exposure and adverse neurodevelopmental outcomes, with pooled odds ratios or relative risks for ADHD ranging from 1.2 to 1.4, and smaller associations for ASD. Sensitivity analyses showed stronger associations with longer or third-trimester exposure. However, sibling-controlled analyses, which accounted for shared familial and genetic factors, attenuated these associations to null. This suggests that observed relationships likely stem from familial or unmeasured confounding rather than a causal drug effect.
Moreover, overlap among primary studies was high (23%), further limiting interpretability. Seven reviews explicitly cautioned against drawing causal conclusions, emphasizing that apparent risks may reflect study bias and design limitations rather than true biological effects.
Conclusion
The collective evidence indicates a weak, non-causal link between maternal paracetamol use during pregnancy and neurodevelopmental disorders in offspring. Most systematic reviews failed to meet methodological standards necessary for high-confidence conclusions.
The review concludes that the existing body of evidence does not demonstrate a clear association between prenatal paracetamol exposure and ADHD or ASD. Apparent associations in whole-cohort studies are likely attributable to familial or unmeasured confounding factors rather than a direct pharmacologic effect.
Source:
https://www.news-medical.net/news/20251111/No-taking-paracetamol-while-pregnant-doesne28099t-cause-autism-or-ADHD-major-review-finds.aspx