Fact Check: Examining the Link Between Prenatal Tylenol Use and Autism Risk

In the wake of recent headlines linking Tylenol to autism, medical experts are emphasizing the medication’s continued safety during pregnancy, while clarifying the science behind these claims.

For decades, Tylenol, with its active ingredient acetaminophen, has been widely regarded as one of the few safe options for pain relief during pregnancy. Unlike ibuprofen or naproxen, which the FDA advises against after 20 weeks of gestation due to potential fetal development risks, acetaminophen remains the go-to recommendation for treating pain and fever in expectant mothers.

Recent media coverage of potential government actions connecting Tylenol to autism has sparked renewed concerns among pregnant women and parents. Reports that Health Secretary Robert F. Kennedy Jr. plans to link Tylenol to autism prompted swift responses from leading medical organizations.

The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine have reaffirmed their longstanding position that acetaminophen, when used appropriately, remains safe during pregnancy.

“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.

Medical professionals emphasize that avoiding treatment for conditions like fever during pregnancy may actually pose greater risks than taking acetaminophen. The Centers for Disease Control and Prevention notes that untreated fever during pregnancy has been linked to birth defects, while the Society for Maternal-Fetal Medicine warns that untreated pain and fever increase risks of adverse outcomes including preterm birth.

Despite years of research, no studies have established that acetaminophen causes autism. This distinction is crucial, as scientific terminology can often confuse public understanding. Terms like “association,” “correlation,” and “increased risk” frequently appear in research papers but do not indicate causation.

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

The scientific literature on this topic remains mixed. Some studies have found positive associations between prenatal acetaminophen exposure and neurodevelopmental disorders, including a 2025 Mount Sinai review. However, the largest and most rigorous study on this subject, published in 2024, found no evidence supporting increased risk of autism, ADHD, or intellectual disability associated with acetaminophen use during pregnancy.

This 2024 study, which examined data from nearly 2.5 million births in Sweden over 24 years, initially found a statistical association between acetaminophen use and developmental conditions. However, when researchers compared siblings born to the same mothers—effectively controlling for genetic and environmental factors—the association disappeared.

Brian Lee, a Drexel University epidemiology professor who co-authored the study, explained this phenomenon: “A mother’s genetic predisposition for autism and ADHD, which is also genetic, is associated with greater pregnancy pain, more headache and migraine, and more use of pain-relieving medications.” This suggests that the same genetic factors that might increase a mother’s likelihood of needing pain relief could also influence a child’s developmental outcomes.

Research methodology also presents challenges. Many studies rely on mothers self-reporting medication use, sometimes years after pregnancy. This introduces potential recall bias, especially if parents of children with developmental conditions are more likely to remember taking medications during pregnancy due to concerns about possible connections.

Autism research has identified hundreds of genes linked to the condition, along with environmental factors including parental age, low birth weight, and illness during pregnancy. This complex etiology makes it difficult to isolate any single factor as causative.

For expectant mothers weighing their options, medical organizations continue to recommend acetaminophen as the safest choice for necessary pain and fever management during pregnancy, while emphasizing appropriate dosing and consultation with healthcare providers.

“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,” Dr. Zahn concluded.