Large analysis shows association but does not prove pain reliever causes disorder
Women who take acetaminophen during pregnancy are more likely to have a child with attention-deficit/hyperactivity disorder than are women who don’t, according to an analysis of nearly 41,000 pairs of mothers and children in a Danish birth registry.
Researchers found that more than half of the women, who gave birth between 1996 and 2002, had used the pain reliever during pregnancy. Followup questionnaires when the children were 7 years old revealed that children whose moms used any acetaminophen during pregnancy were 37 percent more apt to be diagnosed with ADHD or a related disorder than children whose moms didn’t use the drug. If the women used it in all three trimesters, the apparent risk for offspring was 61 percent higher than for children whose mothers didn’t use the drug. Out of nearly 41,000 children, fewer than 1,000 were diagnosed with ADHD and related disorders.
The data, reported February 24 in JAMA PEDIATRICS, establish an association and not cause and effect. But the researchers note that acetaminophen, also sold as Tylenol or Panadol, can cross the placental barrier and may affect hormones in a fetus.
Editor's Note: This story was updated March 18, 2014, to clarify that the followup data came from a questionnaire..
Z. Liew et al. Acetaminophen use during pregnancy, behavioral problems, and hyperkinetic disorders. JAMA Pediatrics. Online February 24, 2014. doi:10.1001/jamapediatrics.2013.4914.
S. Mazaud-Guittot et al. Paracetamol, aspirin, and indomethacin induce endocrine disturbances in the human fetal testis capable of interfering with testicular descent. Journal of Clinical Endocrinology and Metabolism. Vol. 98, November 2013, p. 1757. doi: 10.1210/jc.2013-2531.