Maternal paracetamol use during pregnancy and child IQ at age 7: A prospective cohort study

BACKGROUND: Paracetamol is the most used medication during pregnancy, and concerns have been raised regarding potential associations with child neurodevelopment. OBJECTIVE: To investigate whether maternal paracetamol use during pregnancy, assessed by self-reports and urinary concentrations, was associated with intelligence quotient (IQ) in children aged 7. METHODS: The study used data from the Odense Child Cohort, Denmark, including 2448 pregnant women enrolled between 2010 and 2012. The women completed three questionnaires on paracetamol use during pregnancy; a subgroup of 518 had urinary paracetamol concentrations measured at gestational week 28. Concentrations >4000 ng/mL indicated use within the past 48 h, whereas >2000 ng/mL reflected earlier use. Child IQ was evaluated using four subscales from the Wechsler Intelligence Scale for Children - Fifth Edition. Propensity score-weighted regression models estimated differences in IQ points between users and non-users. RESULTS: A total of 1162 mother-child pairs were included; 65% (N = 777) reported paracetamol use during pregnancy. Self-reported use was non-significantly associated with a reduction of 1.3 IQ points (95% CI -3.0, +0.3). Paracetamol was detected in all urine samples, with 6% indicating recent use. Children of mothers with high urinary concentrations >4000 ng/mL, indicating recent use, showed a non-significant reduction of 1.6 IQ points (-5.9, +2.7). Similar results for concentrations >2000 ng/mL. Analyses excluding women with infections or other indications were compatible with main findings. CONCLUSION: These results suggest a potential association between paracetamol use during pregnancy and reduced IQ in children. Caution is needed, given non-significant estimates, limitations of self-reported data and concentrations reflect only recent use.