United States President Donald Trump just lately claimed that utilizing the frequent painkiller acetaminophen (also referred to as paracetamol and by the model identify Tylenol within the US) throughout being pregnant is fuelling the rise in autism diagnoses. He then went on to recommend pregnant girls ought to “tough it out” somewhat than use the frequent painkiller in the event that they expertise fever or ache.
This announcement has precipitated alarm and confusion worldwide. However regardless of Trump’s declare, there isn’t a robust scientific proof to again it up. Our examine of practically 2.5 million births in Sweden revealed in 2024 reveals no proof that acetaminophen use throughout being pregnant will increase a toddler’s danger of autism. That is the most important examine performed on the topic so far.
To grasp whether or not acetaminophen actually poses a danger in being pregnant, we turned to Sweden’s nationwide well being registers, that are among the many most complete on this planet. Our examine adopted practically 2.5 million kids born between 1995 and 2019, monitoring them for as much as 26 years.
Utilizing prescription information and interviews that midwives performed throughout prenatal visits, we might see which moms reported utilizing acetaminophen (about 7.5% of pregnancies) and which didn’t.
We additionally made certain to account for any variables that will have affected the outcomes of our statistical evaluation – together with controlling for well being elements, equivalent to fever or ache, which might have influenced whether or not or not a mom used acetaminophen throughout her being pregnant. This was to make sure a extra honest comparability between the 2 teams.
We then seemed on the kids’s neurodevelopmental outcomes – particularly whether or not they had been recognized with autism, ADHD or an mental incapacity.
The true power of our examine got here from having the ability to examine siblings. This allowed us to check kids born to the identical mom, the place acetaminophen had been used throughout one youngster’s being pregnant however not the opposite. We in contrast over 45,000 sibling pairs, the place a minimum of one sibling had an autism prognosis.
This sibling design is highly effective as a result of siblings share a lot of their genetics and household atmosphere. This permits us to tease aside whether or not the drug itself – somewhat than underlying household traits or well being circumstances – is answerable for any obvious dangers for neurodevelopmental outcomes.
Acetaminophen use
Once we first seemed on the complete inhabitants, we noticed a sample that echoed earlier research: kids whose moms reported utilizing acetaminophen throughout being pregnant had been barely extra more likely to be recognized with autism, ADHD or an mental incapacity.
However as soon as we ran the sibling comparisons, that affiliation fully disappeared. In different phrases, once we in contrast units of siblings the place one was uncovered within the womb to acetaminophen and one was not, there was no distinction of their chance of later being recognized with autism, ADHD or an mental incapacity.
Our examine shouldn’t be the one one to place this query to the check. Researchers in Japan just lately revealed a examine utilizing an analogous sibling-comparison design, and their outcomes carefully matched ours.
Importantly, they replicated our findings in a inhabitants with a distinct genetic background and the place patterns of acetaminophen use throughout being pregnant are fairly totally different. Almost 40% of moms in Japan reported utilizing the drug throughout being pregnant. Compared, lower than 10% of Swedish moms had used it.
Regardless of these variations, the conclusion was the identical. When siblings are in contrast, there isn’t a proof that acetaminophen use throughout being pregnant will increase the danger of autism or ADHD.
These findings mark an essential shift from earlier research, which relied on extra restricted knowledge, used smaller cohorts and didn’t account for genetic variations. Additionally they didn’t absolutely account for why some moms used ache reduction throughout being pregnant whereas others didn’t.
For instance, moms who take acetaminophen usually tend to even have migraines, power ache, fever or critical infections. These are circumstances which might be themselves genetically linked to autism or ADHD, in addition to a toddler’s chance of later being recognized with considered one of these circumstances.
All these “confounding factors” can create associations that look convincing on the floor, however could not mirror a real cause-and-effect relationship.
That brings us to the true query on many individuals’s minds: what does this imply for those who’re pregnant and coping with ache or fever?
It’s essential to recognise that untreated sickness throughout being pregnant might be harmful. A excessive fever in being pregnant, for instance, is thought to extend the danger of problems for each mom and child. “Toughing it out,” because the president recommended, shouldn’t be a risk-free possibility.
That’s why skilled medical organisations such because the American Faculty of Obstetricians and Gynecologists and the UK’s Medicines and Healthcare merchandise Regulatory Company proceed to suggest acetaminophen (paracetamol) because the most secure fever reducer and ache reliever throughout being pregnant when used on the lowest efficient dose and solely when needed. This has been the steering for many years.
After all, if somebody finds themselves needing to take acetaminophen recurrently over an extended time period, that’s a choice finest made in session with their physician or midwife. However the concept acetaminophen use throughout being pregnant causes autism merely isn’t supported by one of the best out there science.
The higher hazard is that alarmist messaging will discourage pregnant girls from treating ache or fever – placing each themselves and their infants in danger.
Renee Gardner, Principal Researcher, Division of Public Well being Sciences, Karolinska Institutet; Brian Lee, Professor of Epidemiology, Drexel College, and Viktor H. Ahlqvist, Postdoctoral Researcher, Institute of Environmental Drugs, Karolinska Institutet
This text is republished from The Dialog underneath a Artistic Commons license. Learn the unique article.
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