Thinking Public Health

SPH Thinking Public Health gatherings are an opportunity for in-depth conversation within the WashU community about topics of concern in public health. These are moderated, structured, in-person discussions observing the Chatham House Rule to encourage open conversation.

This session’s topic: When Should Public Health Act on Imperfect Data? The Case of Tylenol

Public health officials often must make recommendations amid scientific uncertainty. The recent Tylenol-in-pregnancy controversy highlighted this challenge: In 2025, the Trump administration warned that using acetaminophen (Tylenol) during pregnancy could increase autism risk, despite decades of widespread use and no definitive evidence of harm. This episode raised sharp questions about trust in the messenger and the politicization of evidence, as well as debate over how much evidence is “enough” before taking regulatory action. It underscores a complex, nonpartisan dilemma in public health: how do we balance scientific uncertainty and precaution with the responsibility to communicate risks accurately and maintain public trust?

Readings

Bauer AZ, Swan SH, Kriebel D, et al. “Paracetamol use during pregnancy—a call for precautionary action.” Nature Reviews Endocrinology. 2021;17(12):757-766. Also at: https://doi.org/10.1038/s41574-021-00553-7

Ahlqvist VH, Sjöqvist BA, Dalman C, et al. “Acetaminophen use during pregnancy and children’s risk of autism, ADHD, and intellectual disability.” JAMA. 2024;331(14):1205-1214. Also at: https://doi.org/10.1001/jama.2024.3172

D’Antonio F, Flacco ME, Della Valle L, et al. “Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis.” Lancet Obstet Gynaecol Womens Health. Published Jan, 16, 2026. Also at: https://doi.org/10.1016/S3050-5038(25)00211-0

Frieden TR. “Evidence for health decision making — beyond randomized, controlled trials.” The New England Journal of Medicine. 2017;377(5):465-475. Also at: https://doi.org/10.1056/NEJMra1614394

Parshall A. “Does Tylenol use during pregnancy cause autism? What the research shows.” Scientific American. September 22, 2025. Also at: https://www.scientificamerican.com/article/does-tylenol-use-during-pregnancy-cause-autism-what-the-research-shows/

Prada D, Ritz B, Bauer AZ, Baccarelli AA. “Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the Navigation Guide methodology.” Environmental Health. 2025;24(1):56. doi:10.1186/s12940-025-01208-0. Also at: https://doi.org/10.1186/s12940-025-01208-0