- The risk was notably higher for girls than for boys.
- FDA has considered acetaminophen use safe during pregnancy, but researchers are calling for more study on that.
- Acetaminophen studies have shown mixed results, but some link drug to autism, as well as ADHD.
Fetal exposure to acetaminophen might raise the risk a child will develop attention-deficit/hyperactivity disorder (ADHD), although the drug has long been considered a safe option for pregnant women.
That’s according to a study published this month in Nature Mental Health that says as many as 70% of pregnant women use acetaminophen during pregnancy if they have pain or a fever. The drug is one of the few options considered safe for them by the U.S. Food and Drug Administration.
The researchers from the University of Washington School of Medicine in a news release said there’s “accumulating evidence” of a potential link between prenatal exposure to the anti-inflammatory pain reliever and adverse neurological outcomes, which might also include autism spectrum disorder. They said it’s time for the FDA to reevaluate whether acetaminophen really is low risk during pregnancy.
Written in blood
For the study, they tracked 307 women from 2006 to 2011. The study participants provided blood samples during their pregnancy, which let the team look for plasma biomarkers for acetaminophen.
Then researchers followed the babies the women had for the first eight to 10 years of their lives. They found that the rate of ADHD was 9% for those who didn’t use the drug during pregnancy, but for those who did, the rate of ADHD among the offspring doubled to 18%.
“Acetaminophen metabolites were detected in 20.2% of maternal plasma samples. Children whose mothers had these biomarkers present in their plasma had a 3.15 times higher likelihood of an ADHD diagnosis compared with those without detected exposure,” per the release.
Notably, the association was stronger among daughters than sons. Daughters who were acetaminophen-exposed had a 6.16 times higher likelihood of ADHD. They said the association was “weaker and nonsignificant in males” and reported they could not explain the gender difference in the association.
They also said that “by happenstance and not by design,” the cohort they studied included only Black women, but could be generalized to women and children regardless of race or ethnicity.
Need for more study
During pregnancy, acetaminophen has been considered the safe option for pain and fever. Ibuprofen is more likely to have negative effects for the fetal kidney and heart.
The researchers said there’s a lot more studying to be done on the topic, including looking at whether some women can tolerate the drug in pregnancy safely while others cannot and what makes that difference. They also said the medical guidance should be updated regularly and that patients and their doctors should talk about acetaminophen dosage and what pain the drug can help manage.
“Another drug class such as triptans is safe and effective for managing migraines,” according to lead author Brennan Baker, a researcher at Seattle Children’s Research Institute.
Baker said the findings on acetaminophen in different studies have not always agreed. A recent study in Sweden found no link between acetaminophen use during pregnancy and ADHD. A recent study in Norway did find such a link. Baker noted that the study in Sweden used self-reported data, not the blood analysis that his team used to detect the presence of acetaminophen in blood.
“I think it goes back to how the data was collected,” Baker said in the release. “The conflicting results means more research is needed.”
Other risks?
Acetaminophen use in pregnancy is not the only drug research has linked to ADHD. In January, JAMA Network Open reported that children exposed to steroids — glucocorticoids, specifically — during pregnancy may have higher risk of developing autism or ADHD. That study, by researchers from Aarhus University in Denmark, said some women are given the glucocorticoids to reduce risk of preterm delivery, while others take them to manage autoimmune or inflammatory disorders, according to Medscape.
“Children exposed to steroids because their mothers were at risk for preterm delivery had a 50% higher risk for autism spectrum disorders and a 30% higher risk for ADHD than children who were not exposed but whose mothers were also at risk for preterm delivery,” the article said.
Health care providers and pregnant women need to consider the risks and benefits in making decisions, the researchers said, noting that more study is needed. They also added that alternative medication could be an option.