Recently, alarms were raised about using acetaminophen, or Tylenol, in pregnancy. Many are starting to investigate its potential connections to the rising rates of autism and other developmental disabilities in children. Experts emphasize that the existing research does not support claims of a causal relationship between prenatal acetaminophen exposure and autism. Rather, they point out how critical it is to treat medical conditions such as fever in pregnancy to protect both maternal and fetal health.
Dr. Christopher Zahn, chief of clinical practice at the American College of Obstetricians and Gynecologists (ACOG), asserts that ignoring treatable medical issues, such as fever, poses a greater risk than concerns stemming from inconclusive studies. “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,” he stated.
Scientists have gone to great lengths to determine acetaminophen’s safety in pregnancy. For researchers, they are especially eager to know how it might affect a child’s neurodevelopment. One larger example, published in early 2024, examined data on nearly 2.5 million births between 1995 and 2019 in Sweden. The researchers concluded that their findings provide no evidence that acetaminophen use during pregnancy increases the risk of autism, ADHD, or intellectual disabilities.
The Research Landscape
The new study, the largest conducted on this issue thus far—published in 2024—offers important new information about acetaminophen use in pregnancy. However, researchers could find no correlation between its use and an increased risk of autism or other developmental disorders. It is this study that’s arguably one of only two highest-quality investigations into this field, said Dr. Zahn.
Dr. Judette Louis, the newly appointed dean of Old Dominion University’s medical school, saw a red flag. Findings that do not support a connection between acetaminophen and autism struggle to find their way into print. This can have a broad chilling effect on what the public hears about the safety of that drug during pregnancy.
Christopher J. Smith, chief science officer at the Southwest Autism Research & Resource Center, clarified the distinction between correlation and causation. “Both ‘association’ and ‘increased risk’ are very different from ‘proven causal link’,” he said. This points to the urgent need for robust scientific evaluation before claiming that acetaminophen taken during pregnancy has harmful effects.
Alternative Perspectives
There are conflicting opinions on the link between acetaminophen use and autism. Dr. Erin Clark from the University of Utah pointed out a counterintuitive but interesting finding. She acknowledged that people would more clearly recall if they used acetaminophen and their child went on to develop autism or ADHD, which could bias their risk perception.
In a 2025 review by Mount Sinai, researchers concluded that existing evidence suggests an association between prenatal exposure to acetaminophen and neurodevelopmental disorders. Yet some researchers are still unconvinced about this link. They maintain that it is based on overly narrow and contradictory scientific claims.
Brian Lee, an environmental epidemiology professor at Drexel University who coauthored the 2024 Swedish study. He stressed the importance of doing sibling analyses, in order to control for genetic factors. “When we did a sibling analysis that compared siblings (born to the same mother), the association completely went away,” he stated.
This sibling approach is an important mechanism to help researchers control for multiple confounding variables that can impact outcomes. This helps provide a more accurate assessment of the potential harms associated with acetaminophen use.
The Bigger Picture
The discourse about acetaminophen’s safety in pregnancy needs to step back and wider genetic and environmental risks associated with autism. For example, researchers have identified hundreds of genes that increase the risk of autism. They’ve pin-pointed other contributors, such as parental age at conception, low-birth weights and maternal illness during gestation.
Zoe Gross, director of advocacy at the Autistic Self Advocacy Network, made a critically relevant point. She emphasized that there are alternative explanations for the association between acetaminophen use and autism. This illustrates just how complicated it is to make progress against developmental disorders. It understands that scapegoating one boogeyman is usually too simplistic.
Dr. Salena Zanotti, an obstetrician and gynecologist, pointed out that acetaminophen is one of the safest medications to manage pain and fever during pregnancy. Expecting mothers can feel confident in its safety profile. “When you’re pregnant, it’s riskier to have an untreated fever than it is to take acetaminophen,” she said.
