Could Taking Acetaminophen During Pregnancy Affect Your Child's Behavior?

According to a new study, acetaminophen's effects might last well after you've kicked your headache.

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Add this to the list of things pregnant women might want to avoid: A new study suggests taking acetaminophen during pregnancy might lead to behavioral issues in children. 

Acetaminophen (which is often sold under the brand name Tylenol) has generally been considered safe for pregnant women to take—which is a great thing, since pregnancy can certainly bring on some aches and pains. But recent research begs the question: Do these behavioral concerns outweigh the benefits of using the common over-the-counter solution to safely relieve a pregnant woman's pain or fever symptoms?

According to the researchers behind this study, that's up for debate. The study, which was published online by JAMA Pediatrics, comes from the University of Bristol in the United Kingdom. Researchers observed 7,796 mothers, along with their children and partners, from 1991 to 1992. The study's subjects filled out questionnaires detailing their acetaminophen use at 18 and 32 weeks gestation, as well as when their children were 5 years old. The mothers also self-reported behavioral issues; researchers assessed these when the children were 7 years old.

Of the women sampled, 4,415 (or 53 percent) took acetaminophen at 18 weeks gestation, while 3,381 (or 42 percent) reported using the pain reliever at 32 weeks. Around 89 percent of the women and 84 percent of their partners used acetaminophen after their children were born. About 5 percent of the children involved in the study had behavioral problems.

Here's how the results break down: Acetaminophen use during pregnancy was associated with behavioral issues, but postnatal consumption (by both mothers and their partners) was not. 

The study's results suggest that taking acetaminophen during pregnancy might lead to conduct problems and hyperactivity in children—acetaminophen consumption during the 32nd week of pregnancy was also linked to emotional issues and total difficulties in children. The study does have some limitations, though: Researchers did not receive information about the subjects' dosage or duration of acetaminophen use.

"Children exposed to acetaminophen use prenatally are at increased risk of multiple behavioral difficulties," the authors of the study stated in a news release. However, they added, further studies should be done to determine why this is the case and to test alternative theories, especially given the widespread use of acetaminophen among pregnant women. 

As it stands now, the March of Dimes suggests acetaminophen is the safest over-the-counter pain reliever for expecting moms, as long as it's used according to the directions on the product label. Fit Pregnancy checked in with Siobhan Dolan, MD, MPH, medical advisor to the March of Dimes, for her take: “REPROTOX, the online database that summarizes the birth defects risk of medications, says acetaminophen is considered by many clinicians to be the [pain and fever-reducing] medication of choice during pregnancy. I would agree with that statement," Dr. Dolan said.

If you're concerned about the results of this new study, though, does that mean you should avoid Tylenol (or other brands containing acetaminophen, such as Panadol and Anacin) during pregnancy? Not necessarily. It might simply be a matter of weighing the benefits against the risks. "The risk of not treating fever or pain during pregnancy should be carefully weighed against any potential harm of acetaminophen to the offspring," the study authors said.