Introduction

Acetaminophen (also known Tylenol) is one of the most commonly used over‐the‐counter (OTC) analgesics and antipyretics in pregnancy. It is used to relieve pain (e.g., headaches, musculoskeletal aches), reduce fever, and manage other discomforts. Because many medications are avoided or limited in pregnancy, acetaminophen often becomes a default choice. But how safe is it? What are the risks, limits, and best practices?

What Regulatory Agencies and Label Information Say

FDA Guidance and Labeling

The U.S. Food and Drug Administration (FDA) has conducted reviews of available data on acetaminophen use in pregnancy. As of 2025, the FDA has not found clear evidence that when used appropriately (i.e., correct dose, duration) acetaminophen causes adverse pregnancy, birth, neurobehavioral, or developmental outcomes. Learn more here. 

However, the FDA has initiated changes to labeling (or is in the process of doing so) for acetaminophen products. The updated label will reflect that there is evidence suggesting a possible association between prenatal acetaminophen exposure and neurological conditions such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) in children. These are associations, not proven causal relationships. More information can be found here. 

The label continues to emphasize consultation with a healthcare professional before using any medication during pregnancy; and to use OTC products only as directed. Please visit the US Food and Drug Administration website for additional information. 

Label Dosage and Safety Notes

The FDA label and other product labeling typically specify maximum daily doses for adults (generally up to 4,000 mg in 24 hours for healthy adults) and warn about risks of overdose, particularly liver toxicity. Pregnant persons should consult their obstetric provider regarding what maximum dose and duration are safe in their specific case. Additional information can be found here. 

Labeling also generally cautions about using combination products (e.g., cold/flu medications) because of the risk of accidentally taking multiple acetaminophen containing products and thereby exceeding safe doses. Please visit the US Food and Drug Administration website for additional information. 

What ACOG Says

The American College of Obstetricians and Gynecologists has provided recent and updated guidance on acetaminophen in pregnancy, particularly in light of recent studies. Key points:

ACOG reaffirms that acetaminophen remains the analgesic and antipyretic of choice during pregnancy when needed. It recommends judicious use: the lowest effective dose for the shortest duration necessary.

Regarding recent concerns about neurodevelopmental outcomes (autism, ADHD, intellectual disability): ACOG states that while some observational studies show associations, there is no compelling evidence of causation. The strongest studies (including those with sibling controls) do not support a causal link.

ACOG emphasizes that untreated fever and pain carry their own risks, both for pregnant persons and for fetal health. For example, fever is associated with increased risk for certain birth defects (neural tube defects, etc.), so fever control is not trivial.

Patient counseling is important. Physicians are encouraged to discuss risk/benefit, explain what is known (and what is uncertain), clarify the importance of dose and timing, and reassure patients when acetaminophen is appropriate.

Learn more by visiting the ACOG website. 

Recent Evidence and Risks

While the consensus remains that acetaminophen is reasonably safe under proper use in pregnancy, several recent studies have raised questions, especially about longer duration or higher exposure. Important findings:

A large Swedish population‐based cohort (≈2.5 million children) published in JAMA looked at acetaminophen use in pregnancy and later neurodevelopmental outcomes. In models without sibling controls, there were small increased risks for autism, ADHD, and intellectual disability. But when comparing siblings (thus helping to control for shared familial and genetic factors), these associations largely disappeared. Learn more by visiting the JAMA Network website.

Studies have varied in how well they capture dose, timing, and duration, which are critical variables. Many rely on self‐reports, which have recall bias. Visit the ACOG website for more information.

Some epidemiologic evidence suggests an increased risk of preeclampsia or gestational hypertension with acetaminophen use in the third trimester. One Danish cohort study showed that pregnant women who used acetaminophen in the third trimester had a higher risk of preeclampsia (adjusted RR ~1.40) compared with nonusers. However, causality is not established; confounding variables are possible. Learn more here. 

Practical Recommendations

Based on current evidence, regulatory and professional society guidance, and principles of maternal fetal medicine, here are practical recommendations:

Only use acetaminophen when needed — for fever, moderate pain, or discomfort not manageable by nondrug measures (rest, hydration, nondrug analgesics safe in pregnancy, etc.).

Use lowest effective dose and shortest duration possible.

Avoid exceeding recommended daily maximums and be cautious with combination products (cold/flu etc.) that include acetaminophen to avoid cumulative dosing.

Discuss with your obstetrician or healthcare provider if you have special risk factors: liver disease, frequent long-term pain requiring regular dosing, late‐pregnancy use, or if you are also taking other medications.

Monitor for fever: high fever itself can be harmful (e.g., risk of neural tube defects, etc.), so it needs treatment. Acetaminophen remains the first line.

Avoid NSAIDs (Non-steroidal anti-inflammatory drugs-example ibuprofen, naproxen, etc.) in pregnancy since acetaminophen is safer in many respects. ACOG & FDA both caution about NSAIDs in the third trimester.

Learn more by visiting the U.S. Food and Drug Administration website. 

Uncertainties & Areas Needing More Research

While the overall safety profile is fairly favorable, there remain gaps and uncertainties:

Exact thresholds (dose, timing, duration) beyond which risk might increase are not clearly defined.

Distinguishing associations from causation is difficult in observational studies; more high‐quality research with careful control of confounders is needed.

Effects of repeated or long-term acetaminophen exposure during pregnancy (vs. intermittent, short-term use) still need more study.

Potential impacts on fetal development beyond neurodevelopmental outcomes (e.g., placental effects, blood pressure, or vascular effects) require further evaluation. Some indication (e.g., increased risk of preeclampsia) has appeared but is not definitive.

Learn more at the National Library of Medicine website. 

Conclusion

In summary:

Acetaminophen remains the recommended first‐line analgesic and antipyretic during pregnancy, according to both the FDA labeling and ACOG guidance.

Its use should be judicious: lowest effective dose, shortest duration; pregnant persons and their care providers should weigh the risks of untreated fever/pain against the (currently theoretical) risks of prenatal exposure.

Although some observational studies suggest associations with neurodevelopmental disorders or hypertensive disorders of pregnancy, high quality studies with better control of confounders have not confirmed causation.

Label changes are underway to reflect the evidence more transparently, but these do not currently alter the recommendation for careful use when clinically necessary.

References

ACOG. Acetaminophen Use in Pregnancy and Neurodevelopmental Outcomes. Practice Advisory, September 2025. ACOG 

ACOG. Is it Safe to Take Acetaminophen During Pregnancy? Ask ACOG module. ACOG 

FDA. Acetaminophen Information for Drugs / Drug Safety communication. U.S. Food and Drug Administration 

JAMA study: Acetaminophen Use During Pregnancy and Children's Risk of Autism, ADHD, and Intellectual Disability (Swedish cohort study) JAMA Network

Danish cohort study on acetaminophen and risk of preeclampsia / hypertension in pregnancy.