Prenatal exposure to acetaminophen increases the likelihood that a child will develop attention-deficit/hyperactivity disorder (ADHD), according to a study published today in Nature Mental Health.
Prior research shows that upward of 70% of pregnant women use acetaminophen during pregnancy to control pain or reduce fever. The drug, which is the active ingredient of many pain-relief medications, is one of the few considered safe to take during pregnancy by the U.S. Food and Drug Administration.
The new findings suggest, however, that doctors should reconsider prescribing medications with acetaminophen to mothers during pregnancy, the researchers said.
“Most of the prior studies asked women to self-report whether they had taken Tylenol or anything that contained acetaminophen,” said lead author Brennan Baker, a researcher at Seattle Children’s Research Institute. Baker also works in the lab of Dr. Sheela Sathyanarayana, a UW Medicine pediatrician.
“This medication was also approved decades ago, and may need reevaluation by the FDA,” said Sathyanarayana, the paper’s senior author. “Acetaminophen was never evaluated for fetal exposures in relations to long-term neurodevelopmental impacts.”
Acetaminophen is widely used during pregnancy, with 41–70% of pregnant individuals in the United States, Europe and Asia reporting use. Despite acetaminophen’s classification as low risk by regulatory agencies such as the FDA, accumulating evidence suggests a potential link between prenatal acetaminophen exposure and adverse neurodevelopmental outcomes, including ADHD and ADHD autism spectrum disorder, the researchers noted.
_Acetaminophen metabolites were detected in 20.2% of maternal plasma samples. Children whose mothers had these biomarkers present in their plasma had a 3.15 times higher likelihood of an ADHD diagnosis compared with those without detected exposure. _
The investigators’ analysis used data from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) research cohort, which comprised 1,031 pregnant individuals in Memphis, Tenn., who were enrolled between 2006 and 2011.
Mothers often are advised to turn to acetaminophen, the primary agent in Tylenol, rather than ibuprofen, which is more likely to adversely affect the fetal kidney or heart, Baker said.
“(Acetaminophen) is really the only option to control fever or pain during pregnancy,” he said.
So, what is a mother to do? #
“There is obviously more work that needs to be done in this area,” he said. “And we need to continually update our guidance.”
For example, he suggested, during prenatal visits, patients should discuss the dosage of a drug that contains acetaminophen or talk about what pain it is intended to help manage, he said. Another drug class, such as triptans, is safe and effective for managing migraines, he added.
One study recently released in Sweden, showed no link between maternal acetaminophen use and ADHD in their children; while another study out of Norway, did in fact find a link. The study out of Sweden, however, relied on self-reported data, Baker noted.
“The study out of Sweden, however, reported that only 7% of pregnant individuals used acetaminophen,” Baker noted. “And that study could have underestimated the exposure”.
“I think it goes back to how the data was collected,” he added. “The conflicting results means that more research is needed.”
“Medical societies and the FDA should update guidance on the use of acetaminophen as safety data emerges”, Sathyanarayana said.
Funding #
This study was funded in part by the National Institutes of Health (UG3UH3OD023271).