LOS ANGELES, USA—Taking paracetamol (also known as acetaminophen) while you’re pregnant might increase your baby’s risk of developing neurodevelopmental syndromes like attention-deficit hyperactivity disorder.
A population-based cohort study published in JAMA Pediatrics has reported that babies born to mothers who had taken paracetamol during pregnancy were at higher risk of having a hyperkinetic disorder, of using the ADHD drug methylphenidate, and of having ADHD-like behaviour at seven years of age.
The risk increased with exposure to paracetamol even after adjusting for confounding factors.
Dr. Beate Ritz MD, PhD from UCLA School of Public Health in Los Angeles, co-author of the study, said that they controlled for other medications mothers had taken and for fevers and other infections, and they asked women whether they had a psychiatric diagnosis of depression or anxiety: “It did not change anything,” she noted.
But she didn’t think this was proof of causality: “It’s just that we found no alternate explanation. In practice nobody will tell a woman who has a medical need to not take medication. But the casual over-the-counter use of acetaminophen is certainly not what we want to encourage,” she said.
Dr. Ritz explained that they chose to investigate acetaminophen partly because it’s so widely used (more than half of the women in the study reported using it) and also because it had previously been shown to affect hormones — which can influence brain development. But she said more studies are needed to replicate these findings and to investigate whether the association is causal.
Dr Kate Langley from Cardiff University in Wales, who wrote an editorial on the study, stated that the public should not be alarmed: “There are many reasons why a woman might take paracetamol during their pregnancy and it’s possible that it’s one of these factors, rather than taking the paracetamol itself, which leads to the higher risk of childhood ADHD. So these findings should be taken with caution and shouldn’t change practice at this point,” she noted.
The Los Angeles researchers are now investigating the association of paracetamol with other neurodevelopmental disorders, such as autism.
SOUIRCE: Liew Z. et al., Acetaminophen Use During Pregnancy, Behavioral Problems and Hyperkinetic Disorders, JAMA Pediatr. 2014;168(4):-. doi:10.1001/jamapediatrics.2013.4914.
Cooper M. et al., Antenatal Acetaminophen Use and Attention-Deficit/Hyperactivity Disorder: An Interesting Observed Association But Too Early to Infer Causality, JAMA Pediatr. 2014;168(4):-. doi:10.1001/jamapediatrics.2013.5292.
AUTHOR: Dr. Beate Ritz
Chair, Department of Epidemiology, University of California, Los Angeles, CA.
COMMENT: Dr. Kate Langley, Psychologist, Cardiff University School of Medicine, UK.