FDA Alleges Association Between Prenatal Acetaminophen Use and Autism in Children

The FDA has announced that they are initiating the process for a label change—and alerting physicians across the country—reflecting supposed evidence suggesting that the use of acetaminophen (Tylenol; Kenvue) by pregnant women may be associated with a heightened risk of neurological conditions, including attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), or autism.¹

However, the agency also notes that while numerous studies describe an association between acetaminophen and neurological conditions, a causal relationship has not been established. It also cautioned that acetaminophen is the only OTC drug approved for use to treat fevers during pregnancy; ibuprofen (Advil) and aspirin are generally not recommended until after 20 weeks’ gestation. Overheating, or hyperthermia, during pregnancy—especially of a long duration and during the first trimester—may increase the risk of harm to the baby.^1-4

“The FDA is taking action to make parents and doctors aware of a considerable body of evidence about potential risks associated with acetaminophen,” FDA Commissioner Marty Makary, MD, MPH, said in the news release. “Even with this body of evidence, the choice still belongs with parents. The precautionary principle may lead many to avoid using acetaminophen during pregnancy, especially since most low-grade fevers don’t require treatment. It remains reasonable, however, for pregnant women to use acetaminophen in certain scenarios.” ¹

Medical societies, including the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine decried the actions as “highly concerning to clinicians” and “irresponsible when considering the harmful and confusing message they send to pregnant patients.” Indeed, the highest quality available evidence affirms that there is no link between prenatal acetaminophen use and neurodevelopmental disorders.^5,6

FDA Cites Small Studies, but Larger Research Debunks Suspicion

In its announcement, the FDA cited evidence that has emerged in recent years describing a correlation between acetaminophen use during pregnancy and subsequent ADHD and ASD diagnoses. It specifically cited 2 cohort studies: the 2019 Nurses’ Health Study II, which used a negative control exposure approach to evaluate the association between maternal acetaminophen use and ADHD among 8856 children, and the 2020 Boston Birth Cohort study, which analyzed 996 mother-infant dyads for prospective associations between cord plasma acetaminophen metabolites and ASD and ADHD.^1,7,8

More recently, researchers at the Icahn School of Medicine at Mount Sinai published a systematic review in applying the Navigation Guide methodology and came to the suggestion that prenatal exposure to acetaminophen may increase the risk of neurodevelopmental disorders, including ASD and ADHD. According to these researchers, the findings indicate that higher-quality studies were more likely to show a link between acetaminophen and ASD or ADHD; however, they caution that the study does not establish causation.⁹

According to the ACOG, these studies feature methodological pitfalls, including a lack of a control for confounding factors or the use of unreliable self-reported data. The sample sizes of these studies also pale in comparison to other higher-quality studies available. One such study was published last year in the Journal of the American Medical Association (JAMA); it was nationwide cohort study in Sweden with sibling control analysis, a critical measure for ensuring there are no unobserved familial confounding.^5,10

Across a large sample of 2,480,797 children, preliminary models without sibling control found a marginally increased risk of autism at age 10, ADHD, and intellectual disability. However, according to matched full sibling pairs, there was no evidence that acetaminophen use during pregnancy was associated with autism, ADHD, or intellectual disability. Furthermore, there was no evidence of a dose-response pattern in sibling-control analyses. From this large sample, no associations between ASD or ADHD and acetaminophen use could be firmly established, suggesting that other models claiming such associations was due to unobserved confounding of data.¹⁰

“In more than 2 decades of research on the use of acetaminophen in pregnancy, not a single reputable study had successfully concluded that the use of acetaminophen in any trimester of pregnancy causes neurodevelopmental disorders in children,” Steven J. Fleischman, MD, MBA, FACOG president of ACOG, said in their news release.⁵

Next Steps for Pharmacists

The FDA’s announcement may cause a whirlwind of concerns and questions from both pregnant individuals and mothers. There may be worries regarding past or current acetaminophen use for maternal fevers, headaches as a sign of preeclampsia, and pain, and patients may be concerned that their child is at risk of neurodevelopmental disorders if acetaminophen is taken. Pharmacists can play an essential role in easing patient concerns and planning next steps for their care.¹

Acetaminophen is the only available option for pregnant individuals to reduce fever or mitigate pain. Pharmacists should counsel patients that alternatives, including ibuprofen, should be avoided. According to the FDA’s letter to physicians, pregnant individuals should consider minimizing the use of acetaminophen for routine low-grade fevers, but the decision should be “balanced with the fact that acetaminophen is the safest over-the-counter alternative in pregnancy among all analgesics and antipyretics.” Pharmacists should relay this information to patients, while noting that high-quality research has not found an association between prenatal acetaminophen and ASD or ADHD.¹¹

Above all, pharmacists should ensure that patients who are pregnant continue to effectively manage their pain or fevers as they arise. Preventing severe fevers is a critical aspect of managing the health of both the mother and child.

REFERENCES

1. FDA. FDA responds to evidence of possible association between autism and acetaminophen use during pregnancy. News release. September 22, 2025. Accessed September 23, 2025. https://www.fda.gov/news-events/press-announcements/fda-responds-evidence-possible-association-between-autism-and-acetaminophen-use-during-pregnancy?utm_medium=email&utm_source=govdelivery

2. March of Dimes. Can having a fever while pregnant hurt my baby? Published March 30, 2021. Accessed September 23, 2025. https://www.marchofdimes.org/find-support/blog/can-having-fever-while-pregnant-hurt-my-baby

3. MotherToBaby. Ibuprofen. Published March 1, 2025. Accessed September 23, 2025. https://mothertobaby.org/fact-sheets/ibuprofen-pregnancy/

4. MotherToBaby—Fact Sheets [Internet]. Brentwood (TN): Organization of Teratology Information Specialists; 1994. Fever/Hyperthermia. National Library of Medicine. February 2025. Accessed September 23, 2025.

5. Fleischman J. ACOG affirms safety and benefits of acetaminophen during pregnancy. American College of Obstetricians and Gynecologists. News release. September 22, 2025. Accessed September 23, 2025. https://www.acog.org/news/news-releases/2025/09/acog-affirms-safety-benefits-acetaminophen-pregnancy

6. Phillips G. SMFM response to administration announcement on acetaminophen use during pregnancy and autism. Society for Maternal-Fetal Medicine. News release. September 22, 2025. Accessed September 23, 2025. https://www.smfm.org/news/smfm-response-to-administration-announcement-on-acetaminophen-use-during-pregnancy-and-autism-

7. Liew Z, Kioumourtzoglou MA, Roberts AL, et al. Use of negative control exposure analysis to evaluate confounding: an example of acetaminophen exposure and attention-deficit/hyperactivity disorder in Nurses' Health Study II. Am J Epidemiol. 2019;188(4):768-775. doi:10.1093/aje/kwy288

8. 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. doi:10.1001/jamapsychiatry.2019.3259

9. Mount Sinai study supports evidence that prenatal acetaminophen use may be linked to increased risk of autism and ADHD. Mount Sinai. News release. August 13, 2025. Accessed September 23, 2025. https://www.mountsinai.org/about/newsroom/2025/mount-sinai-study-supports-evidence-that-prenatal-acetaminophen-use-may-be-linked-to-increased-risk-of-autism-and-adhd

10. 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. doi:10.1001/jama.2024.3172

11. FDA. Notice to physicians on the use of acetaminophen during pregnancy. September 22, 2025. Accessed September 23, 2025. https://www.fda.gov/media/188843/download?attachment