Jan 18, 2026
3 min read
When President Donald Trump claimed last year that taking Tylenol during pregnancy may be linked to an increased risk of autism, Dr. Nathaniel DeNicola's office saw an influx of questions and confusion, but only for a week.
When President Donald Trump claimed last year that taking Tylenol during pregnancy could be linked to an increased risk of autism, ob-gyn Dr. Nathaniel DeNicola's office was flooded with questions and confusion — but only for a few days.
"Then a week later, it became a hot topic," said DeNicola, of Newport Beach, Calif., who helps lead the College of Obstetricians and Gynecologists' board of directors on the use of acetaminophen in pregnancy.
At the time, the scientific medical community was "essentially very critical in response to Tylenol's claims of usefulness and safety in pregnancy, and I don't think there was any lasting confusion, at least from those who listened to the medical experts," DeNicola said.
"I think patients will go to their doctor," he added.“The public seems to have taken the lead of the experts who believe their voice on this.
Chicago-based maternal-fetal medicine physician Dr. Lynn Yee said fewer of her patients seem to be concerned about Tylenol now than they were in the fall.
"In September, October, November, the public awareness and attention to this topic increased a little bit, and now, in January, I feel like things are turning around and I'm getting less people asking me about Tylenol or acetaminophen," said Yee, chief of obstetrics and gynecology at Northwestern University's Feinberg School of Obstetrics and Gynecology.
"I'm very proud of our professional organizations, like the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine. They've sent out a lot of messages about the safety of acetaminophen and 'talk to your doctor,'" she said."All these credible organizations have done a commendable job of getting the reports right, and maybe they're working."
Experts stress that there are many possible causes of autism — including genetics, advanced parental age and prenatal exposure to air pollution or certain pesticides — and that the science linking it to acetaminophen is not yet settled.
In guidelines released after Trump's statements in September, ACOG reaffirmed that "acetaminophen remains the analgesic and antipyretic of choice during pregnancy. Judicious use at the lowest effective dose for the minimum necessary duration, in consultation with an obstetrician-gynecologist or other obstetric professional, remains in accordance with best practice."
Acetaminophen, also known as acetaminophen and sold under the brand name Tylenol, is widely considered the only safe option for treating pain or fever during pregnancy.Some common medications, such as ibuprofen or regular aspirin, can increase the risk of serious pregnancy complications.
In many cases, your doctor may prescribe Tylenol to treat pain or fever.Untreated fever can be dangerous to both the fetus and the mother.Experts warn that fever increases the risk of miscarriage.birth defectshigh blood pressureand neurodevelopmental disorders
"Untreated fever can affect fetal neurodevelopment in the short and long term," Yee said."Treating your fever is important because we know that untreated fever during pregnancy is unhealthy for both mother and baby...and we don't have better, safer alternatives to reduce fever during pregnancy."
It is considered that at least 65% of pregnant women use Aceeminophen occasionally during pregnancy.
The medical issue becomes political
The White House issued a report in September referring to various studies that suggest that the use of acetaminophen during pregnancy, especially during pregnancy, can cause long-term adverse effects in children, such as autism or ADHD.
At the time, the US Food and Drug Administration sent a letter to doctors saying, "Physicians should consider reducing acetaminophen use during pregnancy for common low-grade fevers," and in recent years "evidence has accumulated that acetaminophen use by pregnant women may increase the risk of neurological conditions such as autism and ADH."
One of the documents cited by the Trump administration is an analysis of 46 previous studies.That review, published in August in the journal BMC Environmental Health, found evidence of a link between acetaminophen exposure during pregnancy and an increased incidence of neurodevelopmental disorders.
"This association is strongest when acetaminophen is taken for four weeks or longer," said the paper's senior author, Dr. Andrea Baccarelli, dean of the faculty at Harvard.
Baccarelli said he discussed his research with U.S. Health and Human Services Secretary Robert F. Kennedy Jr. in the weeks leading up to the White House announcement.
"At the same time, because acetaminophen is the only drug approved to reduce pain and fever during pregnancy, it remains an important tool for pregnant patients and their doctors. High fever can pose risks to both mother and fetus, including neural tube defects and preterm birth," she said.
"After reviewing the evidence, my colleagues and I recommend a balanced approach to caution: Patients who experience fever or pain during pregnancy should take the lowest dose of acetaminophen, for the shortest time, after consulting with their physician about their own risk-benefit calculation."
Now, new research is adding to the conversation.
'More than peace of mind'
A paper published Friday found no indication that children born to mothers who used acetaminophen during pregnancy were more likely to develop autism.
The study, published in The Lancet Obstetrics, Gynecology and Women's Health, reviewed 43 published studies on prenatal acetaminophen exposure and potential links to neurodevelopment in children, including more than 300,000 pregnancies.17 of these studies were included in the meta-analysis.
"We looked at a range of outcomes, including autism, ADHD and intellectual disabilities," Dr Asma Khalil, an obstetrician and gynecologist at St George's Hospital in London, told a news conference.
The researchers found no evidence that the use of acetaminophen during pregnancy increases the risk of autism, attention deficit/hyperactivity disorder or intellectual disability in children.
The US Department of Health and Human Services said in a statement that the new document does not address questions about the potential risks of Tylenol and excludes many studies on the topic.
In response, Khalil said in an email that the review article “does not discount the evidence” but systematically evaluated all studies and gave greater weight to those “best able to address bias and confounding factors.”
"While we acknowledge that small effects may be a problem at the population level, public health guidelines should be based on the strongest evidence, not signals driven by bias or confounding by indication," he wrote.
Among the studies included in the new analysis was information on siblings whose mother may have used acetaminophen during pregnancy with one child but not the other.
"Meta-analyses comparing siblings provide valuable evidence while accounting for common family and genetic factors," the researchers wrote in their paper.
The publication of these brothers' studies is the strength of new research, Dr.Steven Copp, a senior lecturer in psychology at the University of Portsmouth, who was not involved in the new study, said in a statement distributed by the UK's Media Center.
"Its scientific rigor includes accounting for potential contributors, such as siblings with the condition, as these bloodlines run in families," Kapp said.
"The control of the brothers in these studies shows that the drug does not cause their child's disability. As a neurodivergent researcher and advocate, I think the implication is that people need to stop going down the rabbit hole to avoid social barriers," he said.“Instead, we should focus on making the world a better place for people with disabilities.”
DeNicola, who was not involved in the research, also praised the work, but added that "to date there have only been three sibling studies," as the paper points out.
"So does three studies answer any question? That's a reasonable limit. You always want more information," he said.
In their paper in August, Becquerelly and his colleagues wrote that "sibling comparison analyzes have important limitations that affect their interpretation" and "while sibling comparison studies eliminate the influence of shared familial factors that act as confounders, they also eliminate potential moderators that are commonly shared with acetaminophen, which potentially introduce."
Other potential mediators that may run in families, they say, include disruptions in the body's hormonal system or increased oxidative stress.
But Khalil described sibling comparisons as the "best" study design to account for common factors that may influence autism risk.
"This is probably the best design to help take into account common genetic factors, or a common family environment, meaning these two children are exposed to the same environment, or parental characteristics over time, socio-economic background, educational background, etc. Also, many of the other studies in the literature and published did not fully account for this," he said.
Khalil said the new study came about because he and his colleagues met with pregnant women concerned about the safety of acetaminophen because of Trump's comments last year.
This fear among patients at the time was “certainly my experience,” Khalil said.
National and international health groups "respond quickly by issuing statements trying to reassure pregnant women," he recalled.
