A major new scientific review has found no evidence that taking Tylenol during pregnancy increases the risk of autism or other neurodevelopmental disorders, countering repeated warnings made by Donald Trump and senior officials in his administration.
The analysis, published Friday in The Lancet Obstetrics, Gynaecology, & Women’s Health, concluded that acetaminophen — the active ingredient in Tylenol — does not raise the risk of autism, attention-deficit/hyperactivity disorder or intellectual disability when used during pregnancy. Researchers described the work as the most comprehensive evaluation to date of existing evidence on the topic.
Trump and Health and Human Services Secretary Robert F. Kennedy Jr. warned last fall that pregnant women should avoid Tylenol, citing what they described as a connection to autism. At the time, the claim was not supported by strong scientific consensus and prompted concern among clinicians that pregnant patients might avoid treating fevers or pain, which can pose health risks to both mother and fetus.
In response to the confusion, an international team of researchers from the United Kingdom, Italy and Sweden undertook a detailed review of the scientific literature. They evaluated thousands of studies published through September, narrowing the pool to 43 that met strict criteria for quality and reliability. Studies relying solely on self-reported medication use or lacking adequate medical context were excluded.
The researchers then assessed the remaining studies for bias and methodological weaknesses and conducted deeper analyses of the strongest data sets, including large sibling-comparison studies. Those studies compared children exposed to acetaminophen in the womb with siblings who were not, helping control for genetic and environmental factors.
Across all three analytical approaches, the findings were consistent: there was no evidence linking prenatal acetaminophen use to autism or related developmental conditions. Researchers emphasized that acetaminophen remains the recommended first-line treatment for pain and fever during pregnancy.
Several independent experts not involved in the study praised its rigor, noting that it went far beyond earlier reviews that had suggested a possible association. Those earlier papers, critics said, often relied on smaller data sets and did not sufficiently account for confounding factors.
The Department of Health and Human Services disputed the study’s conclusions, arguing that concerns remain and pointing to previous research that found associations between acetaminophen and autism. Researchers involved in the new review countered that those studies were limited and did not adequately control for key variables.
Despite the new findings, Trump has continued to warn against Tylenol use during pregnancy. Federal guidance issued last year by the Food and Drug Administration, however, still describes acetaminophen as the safest over-the-counter option for treating pain and fever in pregnant patients, while advising cautious use.
Source: NBC News