The list of medications known to be harmful to a fetus when taken by an expectant mother may have added another, writes Alice Park: acetaminophen:

In a study published in JAMA Pediatrics, an international group of researchers led by Dr. Jorn Olsen, at the University of Aarhus, in Denmark, found a strong correlation between acetaminophen (found in common painkillers like Tylenol) use among pregnant women and the rate of attention-deficit/hyperactivity disorder (ADHD) diagnoses and prescriptions for ADHD medications in their children. Overall, moms who used the pain reliever to treat things like headaches or to reduce fevers saw a 37% increased risk in their kids receiving an ADHD diagnosis and a 29% increased risk in the chances that their kids needed ADHD medications compared with moms who didn’t use the over-the-counter medication at all.


The use of acetaminophen during gestation is very common, and more than half the 64,000 mothers in the study used it while pregnant.  Stronger associations were found in pregnancies where acetaminophen was taken in more than one trimester as well as with increased frequency of use.  In other words, acetaminophen was more likely to cause ADHD in children the more their mothers used it, and for longer periods.  What needs to be studied is whether any acetaminophen — for an occasional headache, for example — is safe during pregnancy.

Dr. Nancy Snyderman’s take is here.