Spanish Birth Cohort

2,644 mother-child pairs

“Prenatal acetaminophen exposure was associated with a greater number of autism spectrum symptoms in males and showed adverse effects on attention-related outcomes for both genders. These associations seem to be dependent on the frequency of exposure.”

Brazilian Birth Cohort

3,566 children assessed

Boys exposed to acetaminophen during their mother’s pregnancy were more likely to demonstrate hyperactivity and inattention, both characteristics of autism.

Swedish Birth Cohort

750 mother-child pairs

Acetaminophen use during pregnancy was associated with language delay, a characteristic of children with a higher chance of developing autism.

Norwegian Birth Cohort

26,613 children

“Long-term exposure [to acetaminophen] (29 days or more) was associated with a two-fold increase in risk of Attention Deficit/Hyperactivity Disorder (ADHD) diagnosis.”

English Birth Cohort

14,062 children

“Children exposed to acetaminophen prenatally are at increased risk of multiple behavioral difficulties, and the associations do not appear to be explained by unmeasured behavioral or social factors linked to acetaminophen use; insofar as they are not observed for postnatal or partner’s acetaminophen use.”

Danish Birth Cohort

64,322 children

“Prenatal use of acetaminophen was associated with an increased risk of Autism Spectrum Disorder (ASD) accompanied by hyperkinetic symptoms... but not with other ASD cases... Longer duration of use (i.e., use for >20 weeks in gestation) increased the risk of ASD or infantile autism with hyperkinetic symptoms almost twofold.”