A decade-spanning study has revealed a troubling side effect when pregnant women take a common painkiller during their pregnancies. The effect of the over-the-counter drug was significantly stronger in female offspring than males.
When women are pregnant, they are often advised to take acetaminophen, most popularly known as Tylenol, to help with pain and fever reduction. That's because the drug is less likely to cause damage to the fetus' kidneys or heart than ibuprofen, commonly known as Advil, and it's considered safe by the FDA for use during pregnancy. As a result, it has been reported that about 65% of expectant moms use acetaminophen as needed.
But now, a study led by researchers at the University of Washington shows a potential drawback of using acetaminophen while pregnant.
After examining blood samples for over 300 women gathered between 2006 and 2011, the team found that those women who tested positive for plasma biomarkers for acetaminophen use gave birth to children who were twice as likely to have attention deficit hyperactivity disorder (ADHD) than those whose blood was negative for the drug use.
Non-acetaminophen moms had children with ADHD at a rate of 9%, while that rate climbed to 18% for those who used the drug. The link between taking acetaminophen while pregnant and ADHD development was about six times stronger in girls than in boys, although the researchers don't know why. And detection of acetaminophen in the second trimester increased the chance of ADHD development in offspring by a factor of about three.
“This medication was also approved decades ago, and may need reevaluation by the FDA,” said Sathyanarayana, the paper’s senior author. “Acetaminophen was never evaluated for fetal exposures in relation to long-term neurodevelopmental impacts.”
The incidence of ADHD development was derived after following the children of the women for 8 to 10 years after they had given their blood samples as part of the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) research study carried out by the University of Tennessee Health Science Center. The participants in that study were all black women, however the researchers say that race does not play a role in their findings, which, they say, extend to all women and children.
Blood evidence
The researchers also indicate that previous work looking at the effects of acetaminophen use during pregnancy has relied largely on self-reporting. By using blood markers, the new study has a level of accuracy that might be absent from past research. For example, in one previous study, blood analysis showed the presence of acetaminophen in 20% of women who reported not taking the drug.
While the researchers believe pregnant women should be aware of their study, they do not suggest that acetaminophen be avoided entirely. “[Acetaminophen] is really the only option to control fever or pain during pregnancy,” said lead author Brennan Baker.
But, Baker says, the findings could lead to more informed conversations between pregnant women and their physicians about pain levels and use of the drug. Also, he says, other drugs might work well in place of acetaminophen. For example, the drug class known as triptans are safe and effective at managing migraines.
“There is obviously more work that needs to be done in this area. And we need to continually update our guidance,” Baker concludes.
The study has been published in the journal Nature Mental Health.
