Is acetaminophen safe in pregnancy? Here’s what the science says.

No, according to the WHO, ACOG and AAP. No studies have shown that acetaminophen causes neurodevelopmental issues.

While health experts advocate limiting acetaminophen use in pregnancy to only when necessary, some of the most reassuring data comes from a 2022 study in the journal The Association for Child and Adolescent Mental Health and a 2024 JAMA study that looked at nearly 2.5 million Swedish children born between 1995 and 2019. Both found no causal link.

The Swedish study found a marginal statistical association between a pregnant person’s use of acetaminophen and an increased risk of autism and attention-deficit hyperactivity disorder (ADHD). But that association disappeared once siblings in the same family whose mothers either did or did not take acetaminophen were compared, lead author Brian Lee, an epidemiologist at Drexel University’s Dornsife School of Public Health, wrote in an email to Live Science.

That makes it unlikely that acetaminophen causes autism. Rather, there are other factors, or confounders, that both make people more likely to take the pain reliever during pregnancy and more likely to have a child with autism. “Association is not causation,” Lee said.

What’s likely behind the association is that people who take acetaminophen are doing so to treat a medical condition such as an infection, fever, headache or migraine, and “all of these factors have been found to be associated with risk of autism in the child,” Lee said.

What’s more, scientists know there’s a large genetic component to autism, and women with genes that raise the risk of neurodevelopmental disorders tend to report more pregnancy pain and use of acetaminophen. That same genetic risk of a neurodevelopmental disorder is passed on to their child, Lee added.

Nevertheless, on Sept. 22, the U.S. Food and Drug Administration announced that it will issue a physician notice and initiate a safety label change for acetaminophen, while the U.S. Department of Health and Human Services (HHS) will launch a public service campaign, HHS announced.