Sibling-matched data in Hong Kong showed that prenatal acetaminophen exposure did not increase autism or ADHD risk.Negative-control analyses suggested that associations seen in earlier studies may reflect maternal health and family factors, not medication effects.The findings align with prior sibling studies and recent Danish evidence showing no excess autism risk with acetaminophen exposure during pregnancy.
A large population-based cohort study in Hong Kong demonstrated that acetaminophen (Tylenol) use during pregnancy was unlikely to increase the risk of autism spectrum disorder or attention deficit-hyperactivity disorder (ADHD) in exposed children.
In sibling-matched analyses, prenatal acetaminophen exposure was not associated with autism (adjusted HR 1.00, 95% CI 0.91-1.11) or ADHD (adjusted HR 1.01, 95% CI 0.93-1.08), reported Eric Yuk Fai Wan, PhD, of the University of Hong Kong, and co-authors.
Findings were consistent regardless of when exposure happened, the cumulative acetaminophen dose, or how often the drug was used, the researchers wrote in JAMA Internal Medicine.
Positive associations were observed in conventional cohort analyses (HR 1.17 for autism; HR 1.23 for ADHD), and also in negative control analyses of pre-pregnancy exposure (HR 1.12 for autism; HR 1.24 for ADHD), Wan and colleagues noted.
