Fact check: Can taking Tylenol during pregnancy cause autism in children?

For years, Tylenol has generally been considered safe for treating pain and fever – even during pregnancy, when doctors discourage patients from using many medications.

Doctors might even recommend taking Tylenol for pain or fever during pregnancy, because, left untreated, they can pose their own health risks.

But recent news reports about the federal government connecting Tylenol to autism have drawn new questions and concerns about the drug.

A few things are clear.

After years of research, no study has shown that acetaminophen, the main ingredient in Tylenol, causes autism. There’s no known single cause of autism, a neurological condition that influences how someone acts and communicates.

But some scientific terms, like “association”, can confuse the issue. Some research says there’s an association between the consumption of acetaminophen during pregnancy and autism. Some other research says there’s no association.

But either way, there’s an important caveat: “Association” is not the same as causation. That means that research showing an association between the medication and autism doesn’t mean the medication caused autism.

Here’s what else you should know.

Doctors say it’s safe to use acetaminophen for fever and pain during pregnancy

After The Wall Street Journal reported on Health Secretary Robert F Kennedy Jr’s plans to link Tylenol to autism, leading maternal and prenatal care organisations reiterated their longstanding support for using acetaminophen during pregnancy.

The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine said acetaminophen is a safe way to treat pain and fever when used in moderation.

“Pregnant patients should not be frightened away from the many benefits of acetaminophen, which is safe and one of the few options pregnant people have for pain relief,” said Dr Christopher Zahn, ACOG’s chief of clinical practice.

In fact, Dr Salena Zanotti, an obstetrician and gynaecologist, told Cleveland Clinic earlier this year that acetaminophen is considered the safest drug to take during pregnancy for fever and pain.

“When you’re pregnant, it’s riskier to have an untreated fever than it is to take acetaminophen,” Zanotti said.

Other common pain relievers, such as ibuprofen or naproxen, aren’t recommended during pregnancy because they could harm fetal development, Zanotti said. The US Food and Drug Administration said as much in 2023, advising that such nonsteroidal anti-inflammatory drugs, or NSAIDs, shouldn’t be used during pregnancy after 20 weeks of gestation.

Having an untreated fever while pregnant can harm a baby

Ignoring medical conditions such as fever that could be treated with acetaminophen during pregnancy is “far more dangerous than theoretical concerns based on inconclusive reviews of conflicting science”, Zahn said.

The Centers for Disease Control and Prevention (CDC) says fever during pregnancy has been linked to adverse outcomes, including birth defects.

Untreated fever and pain during pregnancy have maternal and infant health risks, including preterm birth, according to the Society for Maternal-Fetal Medicine (SMFM).

Research has not shown that using acetaminophen during pregnancy causes autism

No study has shown that using acetaminophen during pregnancy causes developmental disabilities, including autism.

But the language used in scientific research can be confusing. Words like “correlation”, “association”, and “increased risk” in studies about acetaminophen use during pregnancy do not mean that the medication caused a disability like autism.

“Both ‘association’ and ‘increased risk’ are very different from ‘proven causal link’,” said Christopher J Smith, chief science officer at Southwest Autism Research & Resource Center.

The FDA, the SMFM and ACOG have all reviewed the available research on acetaminophen use during pregnancy and subsequent neurodevelopmental issues i