A newly published review of existing scientific studies found no link between taking acetaminophen during pregnancy and autism spectrum disorder or attention deficit/hyperactivity disorder (ADHD) in children, despite recent public concerns and claims from the Trump administration.
The review, published in the BMJ by a research team from the University of Liverpool, looked at 40 studies from around the world that were conducted within the past decade.
While many of those earlier reviews had reported a possible association between prenatal acetaminophen use and neurodevelopmental disorders, most also cautioned that the findings could be skewed by bias, poor study design, or failure to account for family-related factors.
The researchers said confidence in those past reviews was low to critically low under AMSTAR 2 — a widely used tool for rating systematic review quality — citing weaknesses such as missing protocols, incomplete literature searches, and inadequate control of confounding variables.
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Notably, the BMJ team highlighted two high-quality studies that compared siblings where one pregnancy involved acetaminophen exposure and another did not. These "sibling control" studies — conducted in Sweden and Norway — saw initial small increases in autism or ADHD risk vanish once genetic and shared environmental influences were factored in.
Lead author Professor Shakila Thangaratinam of the University of Liverpool said the pattern suggests familial factors, rather than the medication itself, likely explain much of the apparent link seen in traditional whole-population studies.
The researchers said their findings are important given the recent directives from the Trump administration that urge pregnant women to avoid Tylenol over fears it could cause autism.
Medical experts and regulatory agencies in the U.S., U.K., EU, and Australia responded by reassuring expectant mothers that acetaminophen remains the safest recommended treatment for fever and pain during pregnancy.
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The researchers emphasized that withholding acetaminophen in cases of high fever could pose greater risks to both mother and baby, including poor pregnancy outcomes.
The authors of the study stressed that the lack of robust, well-controlled studies reflects a broader problem in women’s health research: underinvestment in rigorous trials during pregnancy. They call for future work that carefully measures drug exposure, uses validated diagnostic tools, and employs multiple analytical methods to rule out bias.
