“Our findings suggest that Tylenol/acetaminophen/paracetamol might not be as harmless as we think,” said the lead doctor on a study in the International Journal of Epidemiology.
Frequent use may be linked to poorer language skills and behavior problems among their children, according to the study. “Long-term use of (acetaminophen) increased the risk of behavior problems by 70 percent at age three,” the researcher said. “That is considerable.”
The developmental problems seen in this study align with symptoms of autism spectrum disorder, though the children had not been diagnosed at age three.
As the most popular over-the-counter drug in the U.S., Tylenol has been extensively studied in relation to premature birth and miscarriage, with no connections found.
But its maker Johnson & Johnson periodically comes under fire for the drug’s small therapeutic index – that is, the difference between an effective dose and a dangerous dose is quite small. So interest in investigating the drug persists.
The new study is the first to look at young children whose mothers took Tylenol while pregnant. Close to four percent of women took Tylenol for at least 28 days total during pregnancy. Their children seemed to have poorer motor skills than kids whose mothers had taken the drug fewer times or not at all. Tylenol-exposed kids also tended to start walking later, have poorer communication and language skills and more behavior problems.
It’s difficult to define risks for pregnant women and their children, since rigorous tests and controlled studies of drug exposure aren’t ethical. All researchers can do is closely observe women in the real world. But this study involved a large number of women.
Researchers also looked for any link to ibuprofen/Motrin. They found no development problems tied to ibuprofen.