Acetaminophen, the active ingredient in Tylenol, has been used for over a century to treat pain and fevers and is one of the most studied medications in history.
Though there is public debate about whether taking acetaminophen while pregnant can cause autism in children, there is no scientific evidence for this claim, according to experts.
"Tylenol is safe to use during pregnancy," says Caitlin Baptiste, MD, an OB/GYN and medical geneticist at Columbia. "If you're pregnant and your doctor recommends Tylenol for pain or fever, it's riskier for you and your baby if you don't take it."
Dr. Baptiste and two of her colleagues address top questions about Tylenol and autism, including what the science says-and what researchers are still learning.
Is there evidence that using Tylenol during pregnancy causes autism?
"Overall, the evidence indicates that Tylenol does not contribute to developing autism," says Columbia psychiatrist, neuroscientist, and autism expert Jeremy Veenstra-VanderWeele, MD, who notes other factors that have impacted autism rates. "The recent increase in autism diagnoses is largely driven by changes in our diagnostic criteria, increased screening, and increased awareness."
In understanding the current debate, it's important to note the language used in research. Some studies that analyzed medical records and interviewed mothers about their medication use during pregnancy found that taking Tylenol was "associated" or "correlated" with an increased risk of having children with autism or ADHD. An association This means the trends show a similar pattern, not that one causes the other (also known as a causal relationship). Meanwhile, many larger, more thorough studies have not found an association.
"We've known for a very long time that infections during pregnancy raise the risk for autism. And of course, infections can result in fever, which might cause pregnant people to take Tylenol," says Joshua Gordon, MD, PhD, a psychiatrist and neuroscientist at Columbia and executive director of the New York State Psychiatric Institute. "These studies have not adequately considered that infection during pregnancy is linked to both Tylenol use and autism separately."
Why is there disagreement about what causes autism?
Scientists and health care providers agree that genetics plays the largest role in developing autism, accounting for around 80% of the risk, says Dr. Veenstra-Vanderweele. In around 15-20% of autism cases, the cause can even be pinpointed to a change in a single gene.
Although genetics is by far the most important factor, environmental influences, like infections during pregnancy and exposure to pollution, may also play a role. Understanding these influences and how they may contribute is at the center of the debate.
"There's not a lot that we can do about genetic factors, but we could intervene on the environmental factors to reduce the risk of autism," says Dr. Gordon. "We're not saying Tylenol couldn't be a factor, but overwhelmingly the data make it clear that there are others that are of greater importance in the battle against the most severe forms of autism."
Is Tylenol safe to take during pregnancy?
Yes, in fact, acetaminophen is the only over-the-counter pain reliever and fever reducer that the FDA has approved for use during pregnancy. Other pain relievers such as ibuprofen and aspirin belong to a different class of medications called NSAIDs, which are known to cause serious issues in developing babies' blood vessels.
Like any other medication, Tylenol should be used only when necessary.
What should pregnant people do if they have pain or a fever?
Always talk to your obstetrician. "You are being an excellent and responsible parent by taking care of yourself and your baby by treating whatever condition is causing these symptoms," says Dr. Baptiste.
Caitlin Baptiste, MD, is an assistant professor of obstetrics and gynecology, maternal-fetal medicine (MFM) physician, and medical geneticist at Columbia. She specializes in preconception counseling for genetic disorders, caring for people with genetic disorders during pregnancy, and pregnancies with a genetic diagnosis.
Jeremy Veenstra-VanderWeele, MD, is the Ruane Professor of Psychiatry at Columbia University and the director of the Division of Child & Adolescent Psychiatry at NewYork-Presbyterian/Morgan Stanley Children's Hospital, New York State Psychiatric Institute (NYSPI), and Columbia University.
Joshua A. Gordon, MD, PhD, is a psychiatrist and neuroscientist at Columbia. He is the Chair of the Department of Psychiatry, executive director of the New York State Psychiatric Institute, and Psychiatrist-in-Chief at New York-Presbyterian Hospital-Columbia University Irving Medical Center.
