Concerns have persisted for years regarding the potential link between acetaminophen use during pregnancy and an increased risk of developmental conditions, such as autism spectrum disorder. However, despite these concerns, no studies have established a direct causal relationship.
The U.S. Health and Human Services Secretary, Robert F. Kennedy Jr., has prioritized finding potential causes of autism, launching the $50 million Autism Data Science Initiative in May 2025. In September 2025, the department issued a warning about the potential connection between acetaminophen and autism, highlighting the importance of further research into this area.
Prominent researcher Dr. Zeyan Liew, Associate Professor at the Yale School of Public Health, has dedicated years to studying neurodevelopmental disorders. Dr. Liew emphasizes that while there have been several large observational studies indicating an association between frequent or prolonged acetaminophen use during pregnancy and higher rates of neurodevelopmental disorders in children, these studies do not provide conclusive evidence of a causal relationship. Factors such as underlying illnesses or genetic predispositions could play significant roles in the development of autism.
Despite ongoing investigations, including Dr. Liew’s current extensive research into this matter, health authorities like the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention maintain their stance. They continue to recommend acetaminophen as the safest over-the-counter pain reliever for pregnant women. Until more definitive findings are available, acetaminophen remains the pain reliever of choice for expectant mothers.
This ongoing research underscores the complexity of understanding developmental conditions and highlights the importance of scientific inquiry in informing public health recommendations. While experts continue to investigate these associations, pregnant women should consult healthcare providers when making decisions about medication use to ensure both maternal and fetal well-being.