Key facts
- A sibling-matched study found no association between prenatal acetaminophen (Tylenol) use and autism or ADHD.
- The analysis included over 124,000 sibling-matched children for autism and over 97,000 for ADHD.
- No link was found regardless of acetaminophen dosage, timing during pregnancy, frequency of use, or maternal age.
- Researchers suggest previous positive findings may be due to unmeasured familial confounding, not a direct drug effect.
- Similar results were observed in large sibling-matched studies in Sweden and Japan.
A recent study employing a sibling-matched design has found no link between prenatal acetaminophen (Tylenol) use and the development of autism or attention-deficit/hyperactivity disorder (ADHD) in children. The research, which included over 124,000 sibling-matched children for the autism analysis and more than 97,000 for the ADHD analysis, aimed to control for genetic and shared environmental factors within families.