According to recently published study in JAMA Pediatrics, women who use acetaminophen in pregnancy are at increased risk of having a child with ADHD. While many books and articles are published each year implicating any number of environmental causes for ADHD, the evidence in this article should not be ignored.
The JAMA study was not designed to show that acetaminophen is the only cause of ADHD. In fact, the authors have stated that they think the cause of ADHD is some interplay of genetics and environment. Their hope was that the study would find some way to modify the environment so that ADHD might be prevented in genetically predisposed persons. Many cases of ADHD were not associated with prenatal exposure to acetaminophen.
The idea that acetaminophen use is linked to ADHD is not a new idea. A review article by Dr. William Shaw, PhD, published in October, 2013, in the Journal of Restorative Medicine, suggested that acetaminophen use in infants, might be responsible for ADHD. Dr. Shaw cited epidemiological evidence showing that the increased usage of acetaminophen is linked temporally with the rise in ADHD diagnoses, as well as biological plausibility data from experiments done in rats.
The main difference between the article in JAMA Pediatrics and Dr. Shaw’s article is that the newer evidence creates a much stronger link between individual use of acetaminophen and ADHD. For example, in the JAMA study women were asked about their medication use before their children developed any behavioral symptoms, avoiding a common problem in research studies, called recall bias (people with the disease recall more exposures than people without the disease, just because they are trying to find a cause for their problem). The results also accounted for the presence of infection in the mother, which would make it confusing as to whether acetaminophen was the problem.
The study was also remarkable for its numbers. It examined the Danish National Birth Cohort, a nationwide study of 64,322 Danish women and their children. The study’s authors found that the risk of ADHD-like behaviors at age 7, receiving a prescription for stimulants, or being diagnosed with hyperkinetic disorder was increased by 13-37 % when the mother had taken acetaminophen during pregnancy, with an increasing risk for mothers who took more of the drug.
More studies will need to be done to sort out why there is an association between prenatal acetaminophen and ADHD. Just because there is an association between acetaminophen use and ADHD does not mean that acetaminophen causes ADHD, or that avoiding acetaminophen will prevent ADHD. However, it is unlikely that we will have answers any time soon, since the timing between the prenatal period and diagnosis of ADHD is on average 7 years or more.
Alternatives to acetaminophen
In the meantime, should pregnant women continue to take acetaminophen? Yes and no. In pregnant women, acetaminophen is commonly recommended for minor aches and pains, as well as for fevers, and a variety of other pain causing conditions. This recommendation hinges on weighing the benefits of treatment versus the risk of side effects. Whether acetaminophen is a good idea depends on what condition is being treated.
Minor aches and pains due to musculoskeletal conditions. Women with pregnancy related muscle and joint pains should consider nonmedicinal alternatives. Physical therapy, spinal manipulation, massage, and some types of exercise can help some types of muscular pains. Cold compresses may be used anywhere and warm compresses may be used in parts of the body distant from the womb (such as the wrists, feet, and head). Be sure to have your doctor approve any kind of therapy during pregnancy and be sure that your therapist knows you are pregnant.
Fever. Elevated body temperature can cause pregnancy complications. Because aspirin and related medications ibuprofen and naproxen can cause certain birth defects and delivery complications, acetaminophen is still the safest fever reducing medication available. Avoid alcohol baths as these pose a potential toxic risk to the fetus and are not very effective.
Moderate to severe pain due to other conditions. Nonmedicinal and medicinal alternatives should be explored with your doctor to determine whether relief from your pain outweighs the risk of taking any pain medication. Steps should be taken to minimize the dose of acetaminophen you receive, but it may be safer to take acetaminophen than other pain relievers or medications, even with the risk of ADHD factored in.