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.