No Link Found Between Tylenol Use In Pregnancy And Autism, ADHD In New Analysis Of “Most Rigorous Evidence”

Acetaminophen, or paracetamol – commonly known by brand names like Tylenol® in the US and Panadol® in the UK and Australia – is one of the world’s most widely used drugs. Recommended for pain relief and as a fever reducer, it’s one of few over-the-counter medication options available to pregnant people.

However, this drug became the center of a media and political frenzy in September 2025 after US President Donald Trump gave in a press briefing a simple message: “Don’t take Tylenol.” The pronouncement came as the Food and Drug Administration (FDA) announced changes to the drug label to highlight the possibility that taking the drug in pregnancy could be linked to neurodevelopmental conditions in the unborn child, including autism and ADHD.

The move by the administration caused uproar. Scientists were quick to counter the claims that Tylenol posed a risk to a developing fetus, citing the lack of clear evidence and conflicting results within the literature. Many pointed to large-scale studies that had found no evidence of such a link. 

Moreover, doctors expressed their concerns that fearmongering around acetaminophen may discourage pregnant people from taking the drug when they really need it. 

“This is dangerous, it's anti-science and it's irresponsible,” commented Mel Merritt, Head of Policy and Campaigns at the National Autistic Society, in a statement at the time.

But history has shown us that when the spark of fear is kindled around a medical product, it can be very hard to extinguish – no matter the quality of the evidence on either side of the argument. Scientists are still fighting against the tide of misinformation suggesting that vaccines cause autism, decades on from the retracted paper that kicked off the modern panic and despite dozens of high-quality studies to the contrary. 

Now, the subject of acetaminophen use in pregnancy has been scrutinized in the gold standard of scientific research: a systematic review and meta-analysis. After examining 43 studies for the former and 17 for the latter, the authors found no “clinically important increase” in autism, ADHD, or intellectual disability when acetaminophen was used as directed during pregnancy.

The gold standard

“This study is a systematic review and meta-analysis, widely considered the gold standard for evaluating evidence, because it uses a prespecified, transparent method to identify and assess all relevant studies rather than selecting a few,” senior author Professor Asma Khalil, Professor of Obstetrics and Maternal Fetal Medicine at City St George’s, University of London and consultant obstetrician, told IFLScience. 

“We then critically appraise study quality, consider potential biases, and, where appropriate, pool results to estimate the overall association.”

“What gives us more confidence here is not just the number of studies, but the quality and design of the strongest ones,” Professor Khalil continued. “In particular, some of the most informative studies use approaches like sibling comparisons and other methods designed to reduce ‘confounding’, for example, the fact that the reason someone takes paracetamol (fever, infection, inflammation, pain) may itself be related to outcomes in the child.”

Professor Khalil’s message to anyone who is pregnant or planning a pregnancy, and has been concerned by media reports about Tylenol, is clear: “Don’t panic and don’t stop needed treatment abruptly based on headlines. This study supports that paracetamol use in pregnancy is not associated with autism, ADHD, or intellectual disability when you focus on the most rigorous evidence.”

Speaking to the Australian Science Media Centre, other experts who weren’t directly involved in this new study agreed. 

“This systematic review and meta-analysis provides some of the strongest evidence to date that paracetamol use during pregnancy is not associated with an increased risk of autism, ADHD, or intellectual disability in children,” said Dr Rudrarup Bhattacharjee, a Postdoctoral Researcher from The University of Adelaide.

“No matter which way the researchers looked at the data, the answer came back the same – there was no association,” said Professor David Trembath, Head of Autism Research at CliniKids at The Kids Research Institute Australia. 

In real life, the risk–benefit decision is rarely ‘medicine versus nothing’.

Professor Asma Khalil

We also asked Professor Khalil about the potential risks of not using acetaminophen in pregnancy when there is a clinical need, such as a fever. 

“Fever in pregnancy is often a sign of infection, and untreated fever (and the underlying illness) can be associated with adverse pregnancy outcomes. In real life, the risk–benefit decision is rarely ‘medicine versus nothing’. It’s medicine versus ongoing symptoms and the condition causing them,” she explained. 

“Paracetamol is generally considered the first-line option for treating pain and fever in pregnancy. The sensible advice remains to use the lowest effective dose for the shortest necessary time, and to seek medical advice if symptoms are severe, persistent, or accompanied by features such as a high temperature that doesn’t settle.”

Clinicians providing medical care during pregnancy effectively have two patients to consider at all times. They must not only think about the immediate impact on the pregnant person, but also potential future impacts on their unborn child that may only become apparent years down the line. 

It’s why historically the medical establishment has been so cautious about approving drugs and products for use in pregnancy, and why clinical trials have generally excluded pregnant people altogether.

But, as Professor Khalil told IFLScience, “exclusion has a downside: it leaves clinicians and patients relying heavily on observational data after a drug is already widely used. There is now a growing consensus internationally that we need better, ethically designed research in pregnancy, because lack of evidence does not equal safety, and it can also lead to harmful under-treatment.”

“This topic underscores the need to continually improve the quality of evidence in pregnancy, so that pregnant people are not left with uncertainty, fear, or mixed messaging.”

The study is published in The Lancet Obstetrics, Gynaecology, & Women’s Health.