Is there a link between taking Tylenol (acetaminophen) during pregnancy and the development of autism?

Acetaminophen Use During Pregnancy and Autism Risk

Based on current clinical guidelines, acetaminophen (Tylenol) remains a reasonable and appropriate medication choice during pregnancy, but should be used judiciously at the lowest effective dose for the shortest duration possible, as the evidence linking it to autism is inconclusive. 1

Current Evidence on Acetaminophen and Neurodevelopmental Outcomes

The Society for Maternal-Fetal Medicine (SMFM) and the American College of Obstetricians and Gynecologists (ACOG) maintain that acetaminophen is an appropriate medication for pain and fever relief during pregnancy 1. However, several observational studies have reported associations between prenatal acetaminophen exposure and neurodevelopmental outcomes:

• Prenatal acetaminophen exposure has been associated with increased risk of autism spectrum disorder (ASD) with hyperkinetic symptoms (HR = 1.51,95% CI 1.19-1.92) 1, 2
• Longer duration of use (>20 weeks in gestation) may increase the risk of ASD with hyperkinetic symptoms almost twofold 1, 2
• A meta-analysis found an association between maternal acetaminophen use during pregnancy and ADHD risk (pooled adjusted RR of 1.25,95% CI 1.17-1.34) 3
• A 2025 evaluation using the Navigation Guide methodology reported evidence consistent with an association between prenatal acetaminophen exposure and increased incidence of neurodevelopmental disorders 4

Important Limitations of the Evidence

The weight of evidence regarding a causal relationship between acetaminophen use and autism is inconclusive and has significant limitations 1:

• Most studies are observational and cannot fully account for confounding factors
• Studies showing associations often specifically link acetaminophen to ASD with hyperkinetic symptoms, suggesting the predisposition may be toward hyperkinetic syndrome rather than autism alone 5, 2
• The 2019 review in the Journal of Child Psychology and Psychiatry concluded that research to date suggests antidepressant use during pregnancy is relatively safe for long-term neurodevelopmental outcomes 6 (Note: while this evidence focuses on antidepressants, it demonstrates the complexity of studying medication effects during pregnancy)

Clinical Recommendations

When considering acetaminophen use during pregnancy:

1. Use the lowest effective dose for the shortest possible duration

   • Maximum recommended dose is 4g daily, though limiting to 3g or less is preferable 1
   • Limit to 325mg per dosage unit in prescription products 1

2. Consider timing and duration of use

   • Third-trimester use and longer duration (>28 days) may carry higher risks 3
   • Avoid prolonged use when possible 1

3. Explore non-pharmacological approaches

   • For mild to moderate pain, consider non-drug alternatives when appropriate 1

4. Monitor for proper dosing

   • Avoid combining with other acetaminophen-containing products to prevent overdosing 1
   • Be aware of potential liver toxicity with chronic use 1

Key Points for Patient Counseling

• Acetaminophen remains widely used during pregnancy (40-65% of pregnant women) 1
• Untreated pain or fever may pose greater risks to pregnancy than judicious acetaminophen use 1
• The evidence linking acetaminophen to autism is inconclusive and has significant limitations 1
• If acetaminophen is needed, use the lowest effective dose for the shortest duration possible 1

This balanced approach acknowledges the potential concerns while recognizing that acetaminophen remains an important option for managing pain and fever during pregnancy when clinically indicated.