- A group of scientists says acetaminophen — sold as brands including Tylenol — in pregnancy could lead to developmental, reproductive problems.
- It is used to treat fevers and as an over-the counter pain medication.
- Experts disagree with the recommendation of scientists, saying that it doesn’t contain new data or raise alarm.
Unlike other over-the-counter pain medications, Tylenol, a popular branded version of acetaminophen, is considered safe in pregnancy for most moms.Medical organizations say it can be used to manage ailments like fever and body aches, and about two-thirds of pregnant people take the drug at some point.
However, a global team of 91 experts, scientists, public-health professionals, and medical doctors warned against the use acetaminophen while pregnant last week. They claimed that it can alter fetal growth and is often overused unnecessarily.
In their statement, published in the journal Nature Reviews Endocrinology, they urge pregnant women to avoid acetaminophen if they can, talk to a clinician if they’re not sure if their symptoms warrant use, and to use as low a dose for as short a time as possible.
Other experts say the statement isn’t different from current guidance — and may be causing undue alarm.
The report says acetaminophen in pregnancy “is something that needs to be looked at, it doesn’t actually provide any concerning data,” Dr. Stephanie Ros, an OB-GYN and maternal-fetal specialist at the University of South Florida, told Insider. “But I think the overall tone made a lot of people concerned.”
Studies have found risks, but some experts say the research is poor quality
In the statement, the scientists say they are “concerned about increasing rates of neurological, urogenital and reproductive disorders.” They also note “disturbing increases” in the number of children with cognitive, learning, and behavioral problems, and point to Tylenol as a potential cause.
They note that Tylenol may have endocrine-disrupting effects, which means it could interfere with natural hormones that promote healthy development. That’s why known endocrine disruptors like phthalates, found in everything from cosmetics to plastics, should be minimized during pregnancy.
The authors also point to animal research linking acetaminophen in utero to reproductive disorders and fertility issues in adulthood. Some human studies, too, have found that the drug is associated with an increased risk of undescended testicles and a reduced anogenital distance (which, in turn, is predictive of decreased fertility) in males, and early puberty in females.
Study authors then reviewed 29 human studies. 26 of these studies found a connection between prenatal Tylenol exposure and developmental issues like ADHD, autism, or decreased IQ. However, medical organizations have emphasized the limits of such studies.
“The two major governing bodies in the field have analyzed these studies and determined that they were of very poor quality and did not have proper quality controls and did not use good scientific method,” Insider previously heard Dr. Laura Laursen from Chicago. “Women should not be worried. Tylenol is safe during pregnancy. Hard stop.”
‘Patients should not be frightened away’
The paper authors call for more thorough epidemiological research on Tylenol in pregnancy. Meantime, they recommend only using Tylenol for fever — which may be linked to birth defects— and skipping it for other issues.
However, Ros told Insider, “tons and tons of exposures” to Tylenol for reasons other than fever, like bodyaches, don’t seem to be linked to any increase in developmental issues.
Scientists recommend that pregnant patients limit Tylenol use to two weeks. Longer durations have been shown to be more closely linked to adverse outcomes.
Christopher Zahn, vice president of practice activities for the American College of Obstetricians and Gynecologists who was not involved in the paper, told Stat “patients should not be frightened away from the many benefits of acetaminophen” since there’s no evidence it directly causes any problems.
“However, as always, any medication taken during pregnancy should be used only as needed, in moderation, and after the pregnant patient has consulted with their doctor,” He added.
Johnson & Johnson, which makes Tylenol, did not immediately respond to Insider’s request for a comment.