A new study published April 24, 2018 in the American Journal of Epidemiology by a team of researchers at the Hebrew University of Jerusalem (HUJ) has found excessive use of acetaminophen during pregnancy increases the risk for development of attention-deficit hyperactivity disorder (ADHD) and/or autistic spectrum disorder (ASD) in offspring.

Acetaminophen, commonly used for treatment of pain and fever, is considered relatively safe and is the most commonly used analgesic and antipyretic used in pregnancy. It is marketed in the United States as Tylenol, and in Israel as Acamol (paracetamol) and Dexamol.

However researchers said, “evidence of neuro-disruptive properties is accumulating” and therefore, they sought to evaluate the risk for ADHD and ASD in the offspring of women exposed to acetaminophen during pregnancy.

The research team, led by Dr. Ilan Matok of the Institute for Drug Research in the School of Pharmacy at HUJ’s Faculty of Medicine and doctoral student Reem Masarwa, conducted a meta-analysis of data covering 132,738 mother and child pairs, with a follow-up period of three to 11 years. Dr. Amichai Perlman and Dr. Hagai Levine of Hebrew University of Jerusalem and Hadassah Medical Center took part in the research as well.

The analysis shows that prolonged exposure to acetaminophen during pregnancy is associated with a 30 percent increase in relative risk for ADHD (compared to those who did not take the medication during pregnancy) and a 20 percent increase in relative risk for ASD. This is the first study of its kind on the subject.

However, researchers warn that the findings should be interpreted with some caution: pain and fever during pregnancy are also damaging to a developing fetus, and infrequent use of acetaminophen is still considered safe under a doctor’s care. If the symptoms persist, the pregnant woman obviously should consult her physician.

“Our findings suggest an association between prolonged acetaminophen use and an increase in the risk of autism and ADHD,” said Dr. Matok. “However, the observed increase in risk was small, and the existing studies have significant limitations.

“While unnecessary use of any medication should be avoided in pregnancy, we believe our findings should not alter current practice and women should not avoid use of short-term acetaminophen when clinically needed.”        (Photo credit: Pixabay / StockSnap)
Reem Masarwa et al, Prenatal Exposure to Acetaminophen and Risk for Attention Deficit Hyperactivity Disorder and Autistic Spectrum Disorder: A Systematic Review, Meta-Analysis, and Meta-Regression Analysis of Cohort Studies, American Journal of Epidemiology (2018). DOI: 10.1093/aje/kwy086