In a White House event on Monday long on confident statements but short on scientific evidence, President Trump and several of his administration’s public health officials asserted that using Tylenol during pregnancy could lead to autism, an unproven claim.
The president, almost yelling at times, exhorted women not to take Tylenol during pregnancy, telling them to “tough it out” through pain and fevers — which can themselves threaten pregnant patients and fetuses — unless their fevers were extreme or their illnesses so severe that they couldn’t stand it. He linked rising rates of autism diagnoses to acetaminophen, the active ingredient in Tylenol. Mr. Trump also stressed that he believed parents should not give their babies Tylenol.
Experts in obstetrics, pediatrics and autism expressed alarm at the claims from Mr. Trump, Health Secretary Robert F. Kennedy Jr. and leaders of the Food and Drug Administration and the National Institutes of Health.
While a number of studies have shown a possible association between Tylenol and autism, others have not, and none have proved causation. Medical experts, including the American College of Obstetricians and Gynecologists, say that Tylenol is safe to take during pregnancy in consultation with a doctor.
What does research say about Tylenol and autism?
No connection has been proven. The findings of a large body of research are inconclusive.
A paper published last month, based on a review of 46 previous studies, found an association between neurodevelopmental disorders and acetaminophen use during pregnancy in more than half of the studies. But the lead author emphasized that the work did not show acetaminophen use caused these disorders — a crucial distinction that Mr. Trump and other officials at Monday’s event elided.
The studies in question cannot prove causation because they were observational, meaning pregnant women were not randomly assigned to use or not use acetaminophen. Rather, researchers looked at whether women had used acetaminophen during pregnancy, and then looked at their children’s neurodevelopmental outcomes.
This type of study is vulnerable to a problem called confounding: The women who took acetaminophen might have differed in other ways from the women who didn’t, and one or more of those other factors could be responsible for the higher rates of neurodevelopmental disorders.
In addition, most of the studies have been retrospective, meaning that they looked at earlier data, some of which may have been self-reported. This can result in errors or bias and make the results more difficult to interpret.
A large study published last year that examined the medical records of nearly 2.5 million children in Sweden suggested that confounding could indeed be a problem. When the researchers looked specifically at siblings, they did not find a connection between acetaminophen use and autism.
Contrary to administration officials’ statements, the Food and Drug Administration, the European Medicines Agency and the Society for Maternal-Fetal Medicine have all said the evidence is inconclusive.
“My view is that it is certainly something important to consider, but I wouldn’t definitely say it is a cause for autism, which is a complex disorder with multifactorial causes,” said Zeyan Liew, an associate professor of epidemiology at the Yale School of Public Health who is researching Tylenol use during pregnancy.
Should pregnant women take Tylenol?
When pain and fever are not treated, it can be harmful to pregnant women and to fetuses. That is an essential fact that was largely left out of the conversation on Monday, said Dr. Judette Louis, the chair of the publications committee for the Society for Maternal-Fetal Medicine.
“People always forget, when they talk about treatments and risks with treatments, they should also be comparing it to the risks of not treating,” Dr. Louis said. She added that she had already heard from obstetricians who planned to stop recommending Tylenol because they feared being sued by a patient whose child was later diagnosed with autism even if the diagnosis was unrelated to the acetaminophen use.
“We’ve been doing so much work getting people to give pregnant women the appropriate treatment, and now this comes along — it’s just a huge blow,” she said.
Deciding whether or not to take Tylenol is a decision that should be made alongside your OB-GYN, Dr. Liew said.
Clinicians will consider the following, he added: If there is fever, how high is it? What are the other symptoms? Is treatment necessary to control the symptoms?
For pregnant women, Tylenol has no equivalent. Over-the-counter pain medications like ibuprofen and naproxen must be avoided, especially after 20 weeks of pregnancy, because they can harm the fetus.
“We don’t tell people to take a Tylenol a day to help keep their pregnancy healthy. We would only tell people to take it if they need it,” said Dr. Steven Fleischman, the president of the American College of Obstetricians and Gynecologists.
Fevers during early pregnancy have been linked to an increased risk of birth defects. Untreated fevers increase the risk of preterm labor as well, Dr. Fleischman added.
“What we’re going to continue to tell our patients is that when needed, Tylenol is considered to be a safe medication to use in pregnancy,” Dr. Fleischman said.
“I think the risk of the fever is higher than any risk that I have seen anywhere related to acetaminophen,” he added.
Are there risks in giving over-the-counter pain medication to babies or children?
Like practically any medication, painkillers can be dangerous in too-high doses. Doctors recommend sticking to a precise dosing schedule based on children’s height and weight. Too much acetaminophen can cause liver damage and liver failure; by some estimates, acetaminophen poisoning causes over 50,000 emergency department visits in the United States each year.
Acetaminophen is a medication that people can “really easily take too much of,” Brennan Baker, a researcher at Seattle Children’s Hospital, said.
Too much ibuprofen can damage kidneys, especially in children who are dehydrated.
Doctors generally do not recommend giving children over-the-counter pain relievers for more than three days in a row.
Ibuprofen drugs, like Motrin or Advil, are usually not recommended for babies under 6 months of age. It’s important to consult a doctor before giving an over-the-counter pain medication to a young infant.
Children are not supposed to take aspirin unless a doctor specifically tells them to, because of a possible link with a rare illness known as Reye syndrome, which can cause brain swelling and liver damage.
“Do you need to treat a temperature of 99? No, I wouldn’t do that. But if you had a baby that had a fever that was high, and you know that febrile seizures occur, I would treat the fever,” Dr. Fleischman said.
Azeen Ghorayshi contributed reporting.