Popular Medication May Be Causing Hyperactive Kids According to study of pregnant women taking acetaminophen By Michael Harthorne, Newser Staff Posted Aug 16, 2016 2:15 PM CDT 32 comments Comments Acetaminophen, the active ingredient in Tylenol, may be linked to an increased risk of hyperactivity in children. (AP Photo/Paul Sakuma, File) (Newser) – A popular medication among pregnant women is linked to higher rates of hyperactivity in children, according to a study published Monday in JAMA Pediatrics. CNN reports acetaminophen is found in Tylenol, as well as cold, flu, and allergy medicines. The study's author, Evie Stergiakouli, says it's "considered safe to use during pregnancy." In fact, acetaminophen is one of the few pain relievers that is considered safe for pregnant women, according to NBC News. That may explain why the study of nearly 7,800 women in the US and Europe found that more than half reported using acetaminophen while pregnant, mostly as a treatment for pain or fever. The study found women who reported using acetaminophen at 18 weeks of pregnancy were more likely to have children with conduct problems and hyperactivity. Women who reported using it at 32 weeks, were more likely to have children with hyperactivity and emotional and conduct problems. Still, only 5% of the children in the study were shown to have any such problems. And medical experts say women shouldn't worry yet and should keep using acetaminophen as directed by their doctors. A spokesperson for the company that makes Tylenol points out the study doesn't show a causal relationship between acetaminophen and hyperactivity.