Acetaminophen Linked to Developmental Delays in Children

Acetaminophen use during pregnancy linked to ADHD and ASD in children

Pregnant women have fewer options for pain medication and it appears acetaminophen is about to leave that short list. (Africa Studio/Shutterstock)

Acetaminophen is a common over-the-counter medication used by about 65 percent of pregnant women according to the clinical journal, American Family Physician. Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are pervasive developmental disorders that, when combined, comprise more than 12 percent of the United States population, or close to 40 million afflicted Americans. Is there a connection between the two?

Acetaminophen, also known as paracetamol or Tylenol, is widely available without a prescription and is primarily used for pain relief and fever reduction. It is also a component of many other drugs, such as those used to treat common cold symptoms, flu, allergies, and sleep issues. For decades, women have been reassured of the safety of this medication when used during pregnancy.

Recently, researchers published a study in JAMA Psychiatry linking acetaminophen use during pregnancy with an increased risk for ADHD and ASD in their children. Some 996 mother-child sets were enrolled in the study and varying degrees of acetaminophen breakdown products were measured in all umbilical cord blood samples. The most stunning finding in this group was the fact that only 33 percent of the children were considered neurotypical, or free from a developmental delay, by the age of 10 years old. I’ve written in the past about the rapid increases in ASD and ADHD prevalence in our children, but the majority of children are still neurotypical today. In this study group, neurotypical children appear to be the minority.

Studies trying to link developmental delays such as ADHD and ASD with acetaminophen have been published in the past, but they all relied on maternal self-reporting. This more recent study relied on objective cord blood data without any of the biases inherent in self-reporting. Children were assigned into one of three groups based on the amount of acetaminophen metabolites found in the cord blood. These breakdown products were reflective of the dose of acetaminophen taken by the mother during pregnancy. The higher the breakdown products, the higher the dose of acetaminophen, the higher the risk of ADHD and ASD.

Researchers corrected for potential interference in the study such as maternal health issues, substance use, preterm birth, child’s age, and gender. Their final conclusion was the children were between 2.5 and 3.5 times more likely to develop ADHD and between 1.5 and 4 times more likely to develop ASD than children whose mothers didn’t use acetaminophen.

Some potential pathways affected by acetaminophen are serotonergic pathways, COX-2 inhibition, and glutathione depletion. All potential targets for delaying neurodevelopment.

The drug is 115 years old, but these findings are recent, revealing how long it can take for the side-effects of common, “safe” medications to be researched. What about the hundreds of other “old and safe” medicines that have safety data dating back before the advent of modern molecular analysis techniques? It may be time to reconsider their safety record as well.

I think it is worth mentioning that although the researchers corrected for diagnosed maternal health issues, that doesn’t mean the mothers were well. Why would a pregnant mother need to use any medication except to suppress undesirable symptoms?

One possibility is that these mothers already had some sort of undiagnosed inflammatory disorder activated within them and they used acetaminophen because of the relative lack of drugs available to pregnant women. Was it the acetaminophen or an undiagnosed underlying problem driving the acetaminophen chronic usage that caused the increase in ADHD and ASD?

A more troubling message from this study is the continuing desensitization to medication usage in our society. In the span of fifty years, we have somehow gone from a society that avoided medication unless absolutely necessary to the era of “lifestyle” medications. We have gone from a healthy skepticism toward medication safety to blind faith in it. This change in viewpoint has opened the door to taking a pill for an ill where ill used to mean serious illness and now seems to mean even minor discomfort. If that healthy skepticism returned, we all might think twice about popping that pill for stiff joint or stomach ache and it may even spare a few of our kids from the effects of ADHD or ASD.

Armen Nikogosian, MD, practices functional and integrative medicine at Southwest Functional Medicine in Henderson, Nev. He is board-certified in internal medicine and a member of the Institute for Functional Medicine and the Medical Academy of Pediatric Special Needs. His practice focuses on the treatment of complex medical conditions with a special emphasis on autism spectrum disorder in children as well as chronic gut issues and autoimmune conditions in adults.