Ontario Autism Coalition Responds to Claims Linking Acetaminophen to Autism

The Ontario Autism Coalition (OAC) is aware of recent announcements from the United States suggesting that acetaminophen use during pregnancy causes autism spectrum disorder (ASD) and that leucovorin could serve as a “cure.” These claims are not supported by credible science. They oversimplify decades of research and cause real harm to both the autistic community and pregnant people alike.

Autism is not a disease that requires a cure. It is a lifelong neurodevelopmental spectrum, encompassing diverse ways of thinking, learning, and experiencing the world. Research consistently points to strong genetic foundations, with additional developmental and environmental factors under study. There is no credible evidence that a single medication causes autism. A recent population-level study in JAMA with 2.4million participants (2025;333(7):607–615) found no association between acetaminophen use in pregnancy and autism or ADHD. The Society of Obstetricians and Gynecologists of Canada (SOGC) and Health Canada have recently reviewed existing evidence, and they maintain that acetaminophen is safe for use during pregnancy.

Studies that are being lauded as evidence of a causal relationship, including the recent systematic review published in August, contain serious methodological limitations, like unreliable self-reported data, smaller sample sizes, and a lack of control for confounding factors. The highest quality studies show no link. We must rely on evidence-based decisions, not the whims of foreign politicians.

The increase in autism diagnoses reflects evolving diagnostic criteria, greater awareness, improved screening tools, and better access to services. More individuals, including previously overlooked groups such as girls and women, gender-diverse people, and racialized individuals, are now being identified. This is a long-term trend, not a sudden epidemic, and is unrelated to vaccines.

The OAC calls on media, policymakers, and the public to reject oversimplified narratives and stand with science. Claims that reduce autism to a single cause or cure are harmful, perpetuate stigma, and distract from what truly matters: improving lives today through access to evidence-based therapies, education, affordable housing, healthcare, and community supports.

Autistic lives are not political tools. We condemn any attempt to use them as such.