How paracetamol during pregnancy may affect a child's risk of ADHD: new evidence from scientists

The findings are based on analysis of maternal blood concentrations of paracetamol metabolites and correlation of these values with ADHD diagnoses in children aged 8-10 years.

Study: Brennan H. Baker et al, "Associations of maternal blood biomarkers of prenatal APAP exposure with placental gene expression and child attention deficit hyperactivity disorder", Nature Mental Health (2025). DOI: 10.1038/s44220-025-00387-6

Key points of the study

1. Sample composition
   Participants were 307 African American mother-child pairs from the CANDLE (Conditions Affecting Neurocognitive Development and Learning in Early Childhood) cohort. Researchers matched blood plasma samples from women in the second trimester of pregnancy with medical records of their children's health.

2. Metabolites of paracetamol
   Metabolomic analysis revealed that 20.2% of the mothers had APAP-specific metabolites in their blood. Children of these mothers had a 3.15-fold higher risk of ADHD (95% CI: 1.20-8.29) than those with no maternal exposure to the drug.

3. Gender differences
   Statistically, girls in the APAP-exposure group showed an even higher risk (6.16 times), while in boys the correlation was weaker and did not reach significance.

4. Effect on placental genes
   In a subgroup of 174 mothers and children, gene expression in the placenta was analysed. Changes were found that depended on the sex of the child. In girls exposed to paracetamol before birth, immune pathways were activated, including increased transcription of the IGHG1 (immunoglobulin heavy chain gamma 1) gene. There was also a decrease in mitochondrial oxidative phosphorylation (mitochondrial oxidative phosphorylation) pathway activity, which has previously been linked to neurological impairment.

5. Potential explanation
   Scientists believe that increased expression of IGHG1 and related immune cascades may partially explain the increased likelihood of ADHD. And the effect was observed even when other factors were taken into account, not just paracetamol use itself.

Practical conclusion

The results are consistent with previous studies reporting possible negative effects of prenatal paracetamol ingestion on the child's neurological development. However, many of the older studies relied only on mothers' words about using the drug. In contrast, this project used objective blood tests, which reduces the risk of bias.

The scientists emphasise that while paracetamol is widely considered to be relatively safe, further research is needed - particularly into the interaction between genetics, the sex of the child and the amount of drug taken. Nevertheless, the findings add to calls for more judicious use of paracetamol during pregnancy unless absolutely necessary.