Children exposed to acetaminophen in the womb do not appear to have an increased risk of autism or attention-deficit/hyperactivity disorder (ADHD), according to a study published today in JAMA. While a broad analysis of Swedish families found a slightly increased rate of these disorders in children exposed to acetaminophen in the womb, the researchers found no evidence acetaminophen was responsible when factoring in genetic or family influence.
“Results of this study indicate that the association between acetaminophen use during pregnancy and neurodevelopmental disorders is a noncausal association.,” wrote Viktor H. Ahlqvist, Ph.D., of the Karolinska Institutet and colleagues. “Results suggested that there was not one single ‘smoking gun’ confounder, but rather that multiple … health and sociodemographic characteristics each explained at least part of the apparent association.”
Ahlqvist and colleagues first examined developmental outcomes of nearly 2.5 million non-twin children born in Sweden between July 1, 1995, and December 31, 2019. The researchers followed the children until the end of 2021 and identified all diagnoses of autism, ADHD, and intellectual disability. Overall, 7.62% of these children were diagnosed with at least one of these neurodevelopmental disorders. The researchers found that children whose mothers used acetaminophen at some point during pregnancy had a 5% increased risk of an autism or intellectual disability diagnosis and a 7% increased risk of an ADHD diagnosis.
However, mothers who used acetaminophen were more likely to have lower education and/or income levels, have a higher body mass index during early pregnancy, smoke during pregnancy, and have a psychiatric diagnosis. The researchers tried to account for these variables and many others (like the use of other pain medications) in their analysis but noted there might be some genetic or family factors they couldn’t account for.
So, as a further step, Ahlqvist and colleagues conducted a sibling control analysis in which they examined families with siblings in which some children were exposed to acetaminophen while others were not. In this model, they found no association between acetaminophen use during pregnancy and risk of a neurodevelopmental disorder. (In an unexpected result, they did find that the use of aspirin was associated with a reduced risk of neurodevelopmental disorders in children; the researchers hypothesized this association reflected individuals who took low-dose aspirin to reduce birthing problems like preeclampsia.)
For related information, see the Psychiatric News stories “Exposure to Valproate in Utero May Increase Risk of Autism, ADHD” and “Most Antipsychotics During Pregnancy Do Not Increase Neurodevelopmental Risks.”
(Image: Getty Images/iStock/Jorge Martinez)
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