Acetaminophen, the most commonly used drug among pregnant women, may be tied to a higher risk of attention deficit hyperactivity disorder (ADHD) in children, according to a new study in Denmark. USA Today reports that the study, published on Monday in JAMA Pediatrics, may cause concern for women who were told that acetaminophen is safe to take while pregnant. Acetaminophen is a pain reliever and fever reducer found in many over-the-counter medications such as Tylenol.
Researchers made use of Denmark’s thorough health records to conduct the study, which involved over 64,000 Danish children born between 1996 and 2002. The mothers of these children were contacted twice during pregnancy and once six months after birth and asked about their use of acetaminophen. ADHD in children was tracked through prescriptions for ADHD medications, diagnoses of “hyperkinetic disorder” and through questionnaires completed by the parents when the children were 7 years of age. About 56 percent of women used acetaminophen during pregnancy, similar to what is seen in the United States.
According to the study, children were 13 percent more likely to show signs of ADHD-associated behaviors, such as hyperactivity and conduct problems, if their mothers used acetaminophen during pregnancy. These children were also 29 percent more likely to get ADHD medications and 37 percent more likely to be diagnosed by hyperkinetic disorder, which equates to the “high end” of ADHD according to Beate Ritz, a study author and epidemiologist at the University of California, Los Angeles.
Ritz says that the researchers began investigating the link between acetaminophen use and ADHD because the drug might disrupt hormones that affect fetal brain development. She says the study highlights that “anything we do in pregnancy we should not do lightly,” The findings of the study are correlational, meaning that it does not define a cause-and-effect relationship. The links that the researchers identified, however, are strong. They exist even after considering mothers’ mental health and other factors that could have caused mothers to take the drug in the first place, such as fevers, infections and inflammation. Ritz says that the association grew stronger with the number of weeks mothers reported taking acetaminophen.
USA reports that Jeff Chapa, director of maternal fetal medicine at Cleveland Clinic who was not involved in the study, says that women should be cautious about taking acetaminophen for aches and pains when a warm bath or massage can help. He says that women should still take the drug for fevers, since that can affect with fetal development. Concerned pregnant women should also not replace acetaminophen with ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDS) because these medications can also affect development and lead to other problems.