Taking acetaminophen (Tylenol) during pregnancy may lead to behavioral problems in children, a new study has found.
British researchers followed 7,796 parent-child pairs, recording parents’ use of acetaminophen during and after pregnancy. They followed the children until they were 5 years old. More than half the mothers used the drug at least once at 18 weeks of pregnancy, and 42 percent at least once at 32 weeks.
Compared with nonusers, use of acetaminophen at 18 and 32 weeks of pregnancy was associated with a 42 percent increased relative risk of conduct problems and a 31 percent higher risk of hyperactivity symptoms in children.
The study, in JAMA Pediatrics, controlled for maternal age and psychiatric illness, alcohol use, possible indications for acetaminophen use and other variables. There was no increased risk either with post-pregnancy use of acetaminophen or with the partner’s use of the drug.
The lead author, Evie Stergiakouli, an epidemiologist with the Medical Research Council Integrative Epidemiology Unit at the University of Bristol, said that the drug may interfere with the body’s hormone systems, which has been shown in animal studies to affect fetal brain development.
Still, she said, acetaminophen is effective at reducing fever, and fever is associated with preterm birth, “so it is important to use it as the physician directs. People should weigh the risks and benefits of using any drug during pregnancy, including acetaminophen.”