KFF’s latest Tracking Poll on Health Information and Trust, fielded a day after the Trump administration warned that taking Tylenol during pregnancy can cause autism in children despite no evidence of a causal relationship, finds that three-quarters (77%) of the public report having heard this claim, and many are unsure whether it is true. Overall, just 4% of adults say it is “definitely true” that taking Tylenol during pregnancy increases the risk of the child developing autism, while a much larger share (35%) say the claim is “definitely false.” Most adults – including majorities across many demographics – express uncertainty, saying the unproven claim is either “probably true” or “probably false.” Belief in this claim is closely tied to partisanship, with most Republicans, including over half of Republican women, saying it is either “probably” or “definitely true.”

This KFF Health Tracking Poll/KFF Tracking Poll on Health Information and Trust was designed and analyzed by public opinion researchers at KFF. The survey was conducted September 23-29, 2025, online and by telephone among a nationally representative sample of 1,334 U.S. adults in English (n=1,255) and in Spanish (n=79). The sample includes 1,026 adults (n=64 in Spanish) reached through the SSRS Opinion Panel either online (n=1,004) or over the phone (n=22). The SSRS Opinion Panel is a nationally representative probability-based panel where panel members are recruited randomly in one of two ways: (a) Through invitations mailed to respondents randomly sampled from an Address-Based Sample (ABS) provided by Marketing Systems Groups (MSG) through the U.S. Postal Service’s Computerized Delivery Sequence (CDS); (b) from a dual-frame random digit dial (RDD) sample provided by MSG.