Tylenol in Pregnancy and Autism: What the 2025 FDA Label Change Means and What Studies Show

Does taking Tylenol during pregnancy cause autism or ADHD? It has not been shown to. Many observational studies link prenatal acetaminophen use to slightly higher rates of autism and ADHD, and in September 2025 the FDA began adding a warning about a possible association. But the largest study, of 2.48 million Swedish children, found no link when comparing siblings, suggesting family factors explain the pattern. The FDA itself said a causal relationship has not been established.

Acetaminophen, sold as Tylenol and in many generic products, is the most commonly used pain and fever medicine in pregnancy, taken by more than half of pregnant women worldwide. For years it was considered the safest choice because other common pain relievers carry known risks in pregnancy. That picture became contested as studies reported associations with ADHD and autism, and the debate became national news in September 2025, when federal officials announced a label change and urged pregnant women to limit use, while major obstetric organizations, international regulators, and the manufacturer disputed the strength of the evidence. This article lays out what the research shows on both sides, why scientists disagree, and how pregnant people can make decisions about pain and fever.

What Did the FDA Announce in 2025?

On September 22, 2025, after a White House briefing in which President Trump and federal health officials urged pregnant women to avoid acetaminophen, the FDA announced that it was initiating a label change to reflect evidence that acetaminophen use during pregnancy may be associated with an increased risk of neurological conditions such as autism and ADHD, and it sent a notice to physicians. The agency noted that some studies suggest the risk may be greatest with long-term use throughout pregnancy, encouraged clinicians to use the lowest effective dose for the shortest duration, and stated that a causal relationship has not been established and that there are contrary studies. It also noted that acetaminophen is the only over-the-counter medicine approved to treat fever in pregnancy. The same day, the FDA moved to make leucovorin, a form of folate, available for some patients with cerebral folate deficiency and autism symptoms.

How Did Medical Organizations Respond?

Many pushed back. The American College of Obstetricians and Gynecologists called suggestions that acetaminophen causes autism irresponsible and said the medicine remains appropriate when clinically indicated. The Society for Maternal-Fetal Medicine, the World Health Organization, and the European Medicines Agency reaffirmed that acetaminophen remains a recommended option in pregnancy when used as directed. Kenvue, which makes Tylenol, said it does not believe there is a causal link. Some state officials and researchers supported the more cautious message, arguing that the weight of observational evidence justifies precaution. Reports in 2026 indicated that prenatal acetaminophen use declined after the federal announcement.

What Do Studies Linking Acetaminophen to ADHD and Autism Show?

Several large studies have found associations. A 2014 study in JAMA Pediatrics by Zeyan Liew and colleagues, using the Danish National Birth Cohort, found that children whose mothers reported acetaminophen use during pregnancy had a higher risk of hyperkinetic disorders and ADHD-like behaviors, and the authors reported that results did not appear to be explained by maternal infection, inflammation, or mental health. A 2020 study in JAMA Psychiatry by Yuelong Ji and colleagues measured acetaminophen in umbilical cord blood from 996 births in the Boston Birth Cohort. Compared with the lowest third of exposure, the highest third was linked to about 2.9 times the odds of ADHD and 3.6 times the odds of autism. A 2025 review in Environmental Health by Diddier Prada and colleagues applied the Navigation Guide method to 46 studies: 27 reported positive associations, 9 found none, and 4 suggested protective effects, and higher-quality studies were more likely to show associations. The authors called for advising pregnant women to limit acetaminophen.

What Does the Largest Sibling Study Show?

A different picture. A 2024 study in JAMA by Viktor Ahlqvist and colleagues followed 2,480,797 children born in Sweden from 1995 to 2019, with acetaminophen use recorded during pregnancy rather than recalled afterward. In standard analyses, use was associated with very small increases in risk: hazard ratios of 1.05 for autism and 1.07 for ADHD. But when the researchers compared siblings, children of the same mother where one pregnancy involved acetaminophen and the other did not, those associations disappeared (hazard ratios 0.98 for both autism and ADHD), and there was no dose-response pattern. The authors concluded that associations seen in other analyses may reflect familial confounding, meaning genetic or family factors that influence both the likelihood of taking acetaminophen and the likelihood of a child’s neurodevelopmental diagnosis.

Why Do the Studies Disagree?

Several factors make this question hard. Women take acetaminophen for reasons such as fever, infection, inflammation, headaches, and chronic pain, and some of those conditions may themselves affect fetal brain development, a problem called confounding by indication. Autism and ADHD are strongly heritable, and parents with traits linked to these conditions may differ in health behaviors and medication use. Many studies rely on mothers recalling their medication use years later, which introduces error. Sibling comparisons control for shared genes and family environment but have their own limits, such as smaller numbers and the possibility that differences between pregnancies matter. Cord blood studies measure exposure directly but usually capture only the end of pregnancy, when acetaminophen may have been given during labor. Reasonable scientists weigh these strengths and weaknesses differently, which explains the conflicting conclusions.

Why Does Treating Fever in Pregnancy Matter?

Because fever itself carries risks for the baby. A 2014 systematic review in Pediatrics by Julie Dreier and colleagues found that fever in the first trimester was associated with about 1.5 to nearly 3 times the risk of neural tube defects, congenital heart defects, and oral clefts, and there was some evidence that fever-reducing medicines may lessen that risk. Untreated high fever and severe pain can also stress the pregnancy in other ways. This is why obstetric organizations warn that avoiding acetaminophen entirely when it is needed could cause harm, and why the FDA described it as the only over-the-counter medicine approved for fever in pregnancy.

What Are the Alternatives for Pain and Fever in Pregnancy?

Options are limited. Nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen are generally avoided from about 20 weeks of pregnancy onward because the FDA has warned they can cause rare but serious kidney problems in the fetus and low amniotic fluid, and they are avoided late in pregnancy for other reasons. Aspirin is used at low doses only for specific conditions, such as preventing preeclampsia, under medical supervision. Opioids carry their own risks. Non-drug measures help for many minor complaints: rest, hydration, cool compresses for fever, warm or cold packs for aches, physical therapy for back pain, and sleep and stress management for headaches. For persistent or severe symptoms, a clinician can help weigh options.

How Should Pregnant People Use Acetaminophen Now?

Most medical organizations advise using it when there is a clear reason, such as fever or significant pain, at the lowest effective dose for the shortest time, and not taking it routinely or for long periods without talking to a clinician. Check labels of combination cold and flu products, which often contain acetaminophen, to avoid accidentally doubling doses, and never exceed the maximum daily dose, since high doses can damage the liver. Pregnant people who have been taking acetaminophen and feel worried should not panic; the strongest studies do not show that occasional use causes autism, and stopping needed treatment can carry its own risks. Questions about chronic pain, migraines, or other conditions requiring frequent medicine are best discussed with an obstetrician.

What Questions Can You Ask Your Clinician?

Useful questions include: Is this pain or fever something that needs treatment, and what might be causing it? What dose of acetaminophen should I take, and for how many days at most? Are there non-drug approaches that might help? If I have a chronic condition that causes frequent pain, is there a safer long-term plan? Which combination cold or flu products should I avoid so I do not take extra acetaminophen by accident? When should I call or come in, for example for a fever above a certain temperature? Bringing a list of all medicines and supplements you take, including occasional ones, helps your clinician give advice tailored to your pregnancy rather than relying on general headlines.

How Do Pain and Fever Options in Pregnancy Compare?

Is Frequent or Long-Term Use Different From Occasional Use?

That is where concern is greatest. Several studies that reported associations found larger effects with more frequent use or use across multiple trimesters, and the FDA’s notice mentioned that risk may be most pronounced with chronic use throughout pregnancy. However, long-term use is also more likely among people with chronic pain, migraines, autoimmune conditions, or recurrent infections, which makes it harder to separate the drug from the underlying health problem. In the Swedish sibling analysis, there was no dose-response pattern. For now, a sensible approach is to treat frequent need for pain medicine in pregnancy as a reason to see a clinician, who can look for the cause and consider other treatments, rather than relying on daily acetaminophen without oversight.

What Do Other Countries Recommend?

Most health authorities outside the United States did not change their advice after the 2025 announcement. The World Health Organization and the European Medicines Agency stated that acetaminophen remains safe to use during pregnancy when used as recommended and that current evidence does not show it causes autism. Many national obstetric and pediatric societies issued similar statements. Their guidance generally matches the long-standing advice found on product labels: use the lowest effective dose for the shortest necessary time, and seek medical advice for persistent symptoms. Differences in tone between agencies reflect different judgments about how to communicate uncertainty, rather than different data.

Could Avoiding Acetaminophen Cause Harm?

Possibly, if it leads people to leave fever or significant pain untreated or to switch to riskier medicines. Reports in 2026 indicated that prenatal acetaminophen use fell after the federal announcement, and obstetricians have expressed concern that some patients may avoid treating fevers from infections such as influenza, which carry their own risks for pregnancy. Others may turn to ibuprofen or similar drugs, which are generally avoided later in pregnancy. Clear guidance that distinguishes occasional, necessary use from routine long-term use helps prevent these unintended consequences.

What Is Known About the Causes of Autism?

Genetics plays the largest role. A 2019 study in JAMA Psychiatry by Dan Bai and colleagues analyzed more than 2 million people from five countries and estimated that about 80 percent of the variation in autism risk in the population is due to inherited genetic factors. Environmental factors that have been studied include parental age, preterm birth, certain infections and medications during pregnancy, and maternal health conditions, each with modest effects. The rise in autism diagnoses over recent decades reflects broader diagnostic criteria, greater awareness, and better screening, along with any real changes in risk. Because genetics is so important, studies that cannot account for family background, as sibling comparisons do, are especially vulnerable to misleading results, as our article on earlier autism controversies also illustrates.

What Is Leucovorin, and How Does It Relate?

Leucovorin, also called folinic acid, is a form of folate long used to counter the effects of certain chemotherapy drugs and to treat a rare condition called cerebral folate deficiency, in which folate does not reach the brain normally. Some small studies have reported improvements in language or behavior in autistic children with antibodies that block folate transport to the brain. In September 2025, the FDA moved to make leucovorin available for patients with cerebral folate deficiency and autism symptoms. Experts cautioned that the evidence comes from small trials, that it is not a cure for autism, and that more research is needed to know which children, if any, benefit. It is unrelated to whether acetaminophen causes autism, although both were announced together.

How Should Families Make Sense of Conflicting Headlines?

Look at the type of study as well as its conclusion. Associations from observational studies can reflect real effects or hidden differences between groups; designs that control for family background, such as sibling comparisons, carry extra weight for questions about conditions that run in families. Consider the size of any reported risk: a hazard ratio of 1.05 represents a very small increase even if it were causal. Notice whether organizations with relevant expertise, such as obstetric societies, agree, and why they may disagree with government statements. And remember that the choice is rarely between acetaminophen and nothing; it is between acetaminophen and untreated fever, other drugs with known risks, or non-drug approaches. Discussing these trade-offs with a clinician is more useful than following any single headline.

Common Myths

“Tylenol has been proven to cause autism.” The FDA says a causal relationship has not been established, and the largest sibling study found no link.

“There is no evidence of any association.” Many observational studies report associations, which is why the debate continues.

“Any acetaminophen use during pregnancy is dangerous.” Concerns focus mainly on frequent, long-term use; occasional use for fever or pain is still recommended by obstetric groups.

“Ibuprofen is a safer swap.” NSAIDs are generally avoided from about 20 weeks of pregnancy because of fetal kidney risks.

“Leucovorin cures autism.” Evidence is limited to small studies in specific groups.

Key Terms

Acetaminophen (paracetamol): A pain and fever medicine sold as Tylenol and in many combination products.

Confounding: When a third factor, such as genetics or illness, explains an apparent link between exposure and outcome.

Sibling comparison: A study design comparing siblings to control for shared genes and family environment.

Hazard ratio: A measure of relative risk over time; 1.0 means no difference.

Heritability: The share of variation in a trait in a population attributable to genetic differences.

The Bottom Line

In September 2025, the FDA began adding language to acetaminophen labels about a possible association between prenatal use and autism and ADHD, while stating that a causal link has not been established. Many observational studies report associations, and one review found most studies pointed that way. However, the largest study, of 2.48 million Swedish children, found no link when comparing siblings, suggesting family factors explain much of the pattern, and autism is about 80 percent heritable. Untreated fever carries its own risks. Using acetaminophen when needed, at the lowest effective dose for the shortest time, and discussing frequent use with a clinician is the approach most medical organizations recommend.

Frequently Asked Questions

Is it safe to take Tylenol while pregnant?

Major obstetric organizations, the World Health Organization, and the European Medicines Agency consider acetaminophen an appropriate choice for fever and pain in pregnancy when used as needed at the lowest effective dose for the shortest time. The FDA’s 2025 label action notes a possible association with autism and ADHD but says causation has not been established. Discuss frequent or long-term use with your clinician.

Does acetaminophen during pregnancy cause autism?

Causation has not been shown. Many observational studies find associations, and a 2025 review reported positive associations in 27 of 46 studies. But a Swedish study of 2.48 million children found no association when comparing siblings, suggesting genetic and family factors may explain the link. Autism is estimated to be about 80 percent heritable.

What did the FDA change about Tylenol in 2025?

On September 22, 2025, the FDA began the process of updating acetaminophen labeling to reflect that use during pregnancy may be associated with an increased risk of autism and ADHD, and it notified physicians. It advised the lowest effective dose for the shortest duration, while stating that a causal relationship has not been established and that contrary studies exist.

What should I take for a fever while pregnant?

Acetaminophen remains the only over-the-counter medicine approved for fever in pregnancy, and treating fever matters because fever in early pregnancy is linked to higher risks of some birth defects. Ibuprofen and other NSAIDs are generally avoided from about 20 weeks. Call your clinician for high or persistent fever, which may signal an infection needing treatment.

I took Tylenol during pregnancy. Should I worry?

Occasional use is very common, and the strongest studies that account for family factors do not show that it causes autism or ADHD. If you have concerns about your child’s development, talk with their pediatrician, who can check milestones and arrange evaluation if needed. Early support helps children regardless of cause.

References

1. Ahlqvist VH, Sjöqvist H, Dalman C, et al. Acetaminophen use during pregnancy and children’s risk of autism, ADHD, and intellectual disability. JAMA. 2024;331(14):1205–1214. PMID 38592388
2. Prada D, Ritz B, Bauer AZ, et al. Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the Navigation Guide methodology. Environmental Health. 2025;24(1):56. PMID 40804730
3. Liew Z, Ritz B, Rebordosa C, et al. Acetaminophen use during pregnancy, behavioral problems, and hyperkinetic disorders. JAMA Pediatrics. 2014;168(4):313–320. PMID 24566677
4. Ji Y, Azuine RE, Zhang Y, et al. Association of cord plasma biomarkers of in utero acetaminophen exposure with risk of attention-deficit/hyperactivity disorder and autism spectrum disorder in childhood. JAMA Psychiatry. 2020;77(2):180–189. PMID 31664451
5. Dreier JW, Andersen AM, Berg-Beckhoff G. Systematic review and meta-analyses: fever in pregnancy and health impacts in the offspring. Pediatrics. 2014;133(3):e674–e688. PMID 24567014
6. Bai D, Yip BHK, Windham GC, et al. Association of genetic and environmental factors with autism in a 5-country cohort. JAMA Psychiatry. 2019;76(10):1035–1043. PMID 31314057
7. U.S. Food and Drug Administration. FDA responds to evidence of possible association between autism and acetaminophen use during pregnancy. September 22, 2025. fda.gov

Last updated: October 10, 2026