Is there a correlation between Tylenol (acetaminophen) use during pregnancy and the risk of autism?

Correlation Between Acetaminophen Use During Pregnancy and Autism

Current evidence suggests a possible association between prenatal acetaminophen exposure and increased risk of autism spectrum disorder (ASD), particularly when accompanied by hyperkinetic symptoms, but the evidence is not conclusive enough to establish causality.

Current Evidence on Acetaminophen and Neurodevelopmental Outcomes

Association with Autism and ADHD

• Multiple studies have found associations between maternal prenatal acetaminophen use and neurodevelopmental outcomes:
  • Risk ratios of 1.19 (95% CI, 1.14,1.25) for ASD outcomes 1
  • Risk ratio of 1.51 (95% CI 1.19-1.92) for ASD with hyperkinetic disorder 2, 3
  • Longer duration of use (>28 consecutive days) showed a risk ratio of 1.63 (95% CI, 1.23,2.16) for ADHD outcomes 1
  • Use for >20 weeks in gestation nearly doubled the risk of ASD with hyperkinetic symptoms 2, 3

Dose and Timing Considerations

• Evidence suggests a potential dose-dependent relationship 1:
  • Third trimester exposure showed the highest risk for increased ADHD outcomes 1
  • Longer duration of acetaminophen use correlates with higher risk 2, 3

Conflicting Evidence

• The most recent study (2024) found that acetaminophen use during pregnancy was not linked to autism, ADHD, or intellectual disability in offspring 4
• However, a 2025 systematic review using the Navigation Guide methodology found that higher-quality studies were more likely to show positive associations between prenatal acetaminophen exposure and neurodevelopmental disorders 5

Official Guidance and Recommendations

Medical Society Positions

• The Society for Maternal-Fetal Medicine (SMFM) and American College of Obstetricians and Gynecologists (ACOG) maintain that:
  • Acetaminophen is still considered a reasonable and appropriate medication choice for pain and fever during pregnancy 2
  • The weight of evidence is inconclusive regarding a possible causal relationship between acetaminophen use and neurodevelopmental disorders 2

Practical Recommendations

• Healthcare providers should discuss risks versus benefits with patients 2
• When acetaminophen is needed during pregnancy:
  • Use the lowest effective dose for the shortest possible time 2, 6
  • Consider non-pharmacological approaches for mild to moderate pain when appropriate 2
  • Avoid withholding acetaminophen when clearly indicated, as there is no alternative medication with the same safety profile for pain and fever during pregnancy 6

Clinical Implications

Risk Assessment

• The association appears stronger for ASD with hyperkinetic symptoms rather than ASD alone 7, 3
• The predisposition may be toward hyperkinetic syndrome rather than autism specifically 7

Common Pitfalls to Avoid

1. Overreaction: Completely avoiding acetaminophen during pregnancy may lead to untreated pain or fever, which can have their own negative consequences
2. Underestimation: Ignoring the potential risks and using acetaminophen unnecessarily or for prolonged periods
3. Misinterpretation: Confusing association with causation in patient counseling

Balanced Approach

• Acetaminophen remains the safest analgesic and antipyretic for use during pregnancy when indicated 2, 6
• Judicious use is recommended - appropriate indications, lowest effective dose, shortest duration 2, 6
• Document discussions about risks and benefits with patients 2

While research continues to evolve on this topic, current clinical guidelines still support the judicious use of acetaminophen during pregnancy when medically indicated, with appropriate consideration of potential risks and benefits.