Is ADHD Connected to Acetaminophen Use During Pregnancy?

A study has found a possible link between prenatal exposure to the pain reliever acetaminophen and children who later develop Attention Deficit Hyperactivity Disorder (ADHD). Acetaminophen is the active ingredient in Tylenol and other pain and fever medications.

Findings Show Only a Link

Researchers stress that the study, published in the American Medical Association’s JAMA Pediatrics journal, shows only a connection, but does not prove that the medication causes ADHD.

The study looked at 64,000 children in Denmark, who were born from 1992 to 2002. The data showed that ADHD was more common in children whose mothers took acetaminophen while pregnant. Among the findings, children with prenatal exposure to acetaminophen were:

• 13% more likely to develop ADHD behaviors, including hyperactivity and conduct problems.
• 37% more likely to be diagnosed with “hyperkinetic disorder,” which is like a high-end ADHD.
• 29% more likely to be prescribed ADHD medications.

Concern for Pregnant Women

Before this study, doctors had assured pregnant women that acetaminophen was a “safe” drug. The authors did note that it can be important for pregnant women to reduce fever and infection during pregnancy. They emphasized that more needs to be known; these results don’t yet tell them how acetaminophen might be involved with ADHD, at what point the effects are most active, or which people are more at risk.

An editorial in the same journal cautioned that enough is not known yet to indicate anyone should change their practice. Still, women pregnant now or in the near future may want to take notice.

One medical expert in maternal-fetal health said the study should remind pregnant women that for any medication – even those believed to be safe — the best approach is to take it only as needed and then at the lowest dose to be effective.