A new study from the Odense Child Cohort in Denmark examined whether paracetamol (acetaminophen) use during pregnancy is associated with child intelligence at age 7, using two independent exposure measures: repeated self-report questionnaires and urinary paracetamol concentrations. Among 1162 mother-child pairs, 65% of mothers reported paracetamol use during pregnancy. Children’s IQ, assessed via the WISC-V by psychologists blinded to exposure status, showed a small, non-significant reduction associated with use, 1.3 points lower for self-reported users (95% CI: −3.0, +0.3), and 1.6 points lower among those with high urinary concentrations indicating recent use (95% CI: −5.9, +2.7). Notably, paracetamol was detectable in every urine sample collected, consistent with background exposure levels seen in other biomonitoring studies.
Excluding mothers with common indications for paracetamol use, such as infections, did not meaningfully change the results, though the authors note that confounding by unmeasured conditions cannot be fully excluded. Limitations include the use of an abbreviated WISC-V (introducing more measurement error relative to the small effect sizes observed), lack of data on parental IQ, and the inherent constraints of both exposure methods, urinary concentrations capture only recent use, while self-report is subject to recall bias. These findings sit within a mixed literature: a Swedish cohort linked paracetamol exposure to language delay in girls, a Danish cohort found a larger 3-point IQ reduction, while an older U.S. study found no association.
The authors conclude that although the results were not statistically significant, they add to a growing body of evidence on paracetamol and offspring neurodevelopment, and do not rule out a small adverse effect. Given how widely paracetamol is used in pregnancy, they suggest even a modest individual effect could matter at a population level, and call for further research with more detailed exposure and indication data.
Link to full article: https://doi.org/10.1016/j.earlhumdev.2026.106611