A federal appeals court ruling has reopened more than 500 lawsuits claiming that taking Tylenol during pregnancy caused autism or attention deficit hyperactivity disorder in children. But the ruling does not change what the scientific and medical consensus says about acetaminophen's safety in pregnancy, and every major medical organization continues to recommend it as the first-line pain and fever reliever for pregnant people.
On July 13, 2026, the 2nd U.S. Circuit Court of Appeals in Manhattan ruled that a federal district court judge had improperly excluded expert testimony in cases brought by parents and guardians who tied prenatal acetaminophen use to autism and ADHD in their children. The ruling does not determine that Tylenol causes autism. It determines that the excluded testimony reflected methodologies used by other scientists and was admissible as expert opinion, and it returns the cases to the trial court for further proceedings.
Why This Matters
The legal ruling and the scientific question are separate, and conflating them is one of the most damaging things that health media can do. Court decisions about the admissibility of expert testimony do not constitute scientific findings, peer-reviewed evidence, or changes to medical guidance. But when headlines read "Court Revives Tylenol Autism Lawsuits," many pregnant people will reasonably wonder whether they should stop taking Tylenol. That is the question this article exists to answer.
The answer, based on current scientific evidence and the positions of the major medical organizations that care for pregnant people, is that prenatal acetaminophen use at recommended doses and for appropriate durations remains the recommended approach to treating fever and pain in pregnancy.
That said, the evidence surrounding prenatal acetaminophen and neurodevelopmental outcomes is genuinely complex, and readers deserve an accurate summary of what it shows, what it does not show, and what remains uncertain.
What We Know So Far
The 2nd Circuit's July 13 decision reversed the December 2024 dismissal of more than 500 private lawsuits by U.S. District Judge Denise Cote in Manhattan. Cote had excluded testimony from three expert witnesses offered by plaintiffs, ruling that their methodologies were unreliable. The 2nd Circuit panel, in a 64-page decision written by Circuit Judge Guido Calabresi, disagreed.
Calabresi wrote that the excluded testimony from three doctors, including Dr. Andrea Baccarelli, dean of Harvard University's School of Public Health; Dr. Eric Hollander, a psychiatry professor at Albert Einstein College of Medicine; and Dr. Brandon Pearson, a toxicologist at Columbia University, "reflected methodologies used by other scientists constitute acceptable interpretations of scientific evidence where scientists may, and in fact do, disagree," according to Reuters and CNBC.
Calabresi explicitly noted that the appeals court was not deciding whether prenatal acetaminophen causes autism, and was not evaluating whether elected officials should do more to protect public health. The case now returns to Judge Cote for further proceedings, which will include another opportunity for Kenvue to argue the plaintiffs' expert opinions are unreliable under Daubert standards for expert testimony.
Many retailers and pharmacy operators, including CVS, Kroger, Target, Walgreens, and Walmart, were also named as defendants in the original lawsuits.
Where the Science Stands
This is where the legal story requires honest, precise medical journalism.
The scientific literature on prenatal acetaminophen and neurodevelopmental outcomes is large, mixed, and contested. A substantial number of observational studies have found associations between prenatal acetaminophen use and autism or ADHD diagnoses in children. These associations have been reported consistently enough that major scientific bodies have taken note.
However, observational studies cannot establish causation. The primary methodological challenge is confounding by indication: fever and pain during pregnancy, the conditions for which acetaminophen is taken, are themselves associated with adverse pregnancy outcomes and may be independently associated with neurodevelopmental risk. Studies that do not adequately control for the underlying condition being treated cannot distinguish between the effect of the drug and the effect of the condition.
A 2021 consensus statement from a group of scientists and physicians called for cautious use of acetaminophen during pregnancy. But the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and other major U.S. medical organizations reviewed this literature and concluded that the evidence does not support a causal link and that untreated fever and pain during pregnancy carry documented risks to the fetus that may be greater than the uncertain risks suggested by the observational data.
As Kenvue stated: "Credible, independent science shows no proven link between taking acetaminophen and autism or attention deficit hyperactivity disorder. Science matters, and we stand with the many public health and medical professionals who have reviewed the science on this topic and agree."
The issue drew heightened public attention when President Donald Trump and top U.S. health officials suggested a potential link between acetaminophen and autism in September 2025, a development that created public confusion without altering the medical evidence base.
What Doctors and Experts Say
Doctors and medical societies consider acetaminophen the preferred means to treat pain and fever during pregnancy, according to Reuters reporting citing medical organization statements. This consensus has not changed as a result of the appeals court ruling.
Untreated high fever during pregnancy, particularly in the first trimester, is associated with documented risks including neural tube defects and other pregnancy complications. Untreated moderate-to-severe pain can increase maternal stress and have physiological effects on the fetus. The risk-benefit analysis that led major obstetric organizations to recommend acetaminophen as first-line treatment in pregnancy is grounded in this evidence, and that analysis has not changed based on a procedural legal ruling about the admissibility of expert testimony.
At the same time, clinicians consistently advise pregnant people to use acetaminophen at the lowest effective dose for the shortest necessary duration, to document use, and to discuss any prolonged or high-frequency use with their OB or midwife. This is standard pharmaceutical guidance, not a concession that the drug is unsafe.
What the Evidence Shows and What It Does Not
MedicalDaily Evidence Check
- Legal ruling: 2nd U.S. Circuit Court of Appeals, July 13, 2026; reverses dismissal of 500-plus lawsuits against Kenvue; rules expert testimony was improperly excluded; returns cases to district court
- What the ruling determines: That excluded expert testimony was admissible as scientific opinion; that the cases should proceed to further proceedings
- What the ruling does NOT determine: That prenatal acetaminophen causes autism or ADHD; that Kenvue is liable; that medical guidance should change
- Excluded experts: Dr. Andrea Baccarelli (Harvard T.H. Chan School of Public Health dean); Dr. Eric Hollander (Albert Einstein College of Medicine, psychiatry); Dr. Brandon Pearson (Columbia University, toxicology)
- Scientific consensus as of July 2026: No proven causal link between prenatal acetaminophen use and autism or ADHD; major medical organizations (ACOG, AAP) continue to recommend acetaminophen as first-line treatment for fever and pain in pregnancy
- What the observational literature shows: Associations between prenatal acetaminophen use and neurodevelopmental outcomes in some studies; methodological challenges, particularly confounding by indication, prevent causal conclusions
- What readers should know: A legal ruling about expert testimony admissibility is not a finding of causation. Do not change your medication use during pregnancy based on this ruling without discussing it with your OB, midwife, or health care provider.
Who Should Pay Attention?
- Pregnant people currently using acetaminophen for fever or pain management who want to understand what this ruling means for them
- People planning pregnancy who want to understand the state of the evidence before conception
- Parents and families who believe their children may have been affected by prenatal drug exposure and who are following the litigation
- OB-GYNs, midwives, and primary care physicians who will receive patient questions about this ruling and need accurate information to counsel patients effectively
Symptoms and Conditions That May Require Pain or Fever Treatment During Pregnancy
This article is not intended to advise readers on whether to take or avoid any medication during pregnancy. That decision belongs to the patient and their health care team. But the clinical situations in which acetaminophen is commonly considered during pregnancy include:
- Fever above 100.4 degrees F, which carries documented risks to fetal development if untreated, particularly in the first trimester
- Musculoskeletal pain, headaches, and back pain, which are extremely common in pregnancy and can interfere with sleep and function
- Discomfort associated with upper respiratory infections, which cannot be treated with many other analgesics during pregnancy
Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are generally discouraged during specific windows of pregnancy due to risks unrelated to this lawsuit, making the question of which OTC pain reliever is appropriate during pregnancy a real and important clinical one.
What You Can Do Now
- Do not change your prenatal medication use based on news coverage of this legal ruling. The medical guidance around acetaminophen during pregnancy has not changed.
- If you are pregnant and have concerns about acetaminophen use, bring those concerns to your OB-GYN, midwife, or prenatal care provider at your next appointment.
- Use acetaminophen at the lowest effective dose for the shortest necessary duration, which is standard advice for all OTC medications during pregnancy.
- Do not substitute untreated high fever or severe pain for medication avoidance without medical guidance; both conditions carry documented fetal risks.
- For people interested in following the litigation, federal court records and updates from Kenvue's investor relations page will be the most accurate source of case status information.
Cost and Access: What Patients Should Know
Acetaminophen is one of the least expensive and most accessible over-the-counter medications in the United States, available generically at most pharmacies and retailers. Prenatal care visits in which patients can discuss medication questions are covered by Medicaid, CHIP, most private insurance, and ACA marketplace plans.
Patients without insurance or with limited coverage can receive prenatal care through Federally Qualified Health Centers, Title X family planning clinics, and state Medicaid programs. All pregnant people, regardless of insurance status, are encouraged to establish care with an OB-GYN, certified nurse midwife, or family physician.
What Happens Next
The case returns to U.S. District Judge Denise Cote in Manhattan for further proceedings. Kenvue has stated it intends to again challenge the reliability of the plaintiffs' expert testimony under Daubert standards, the legal framework courts use to evaluate the scientific basis of expert opinion. A trial, if the case reaches that stage, would determine whether Kenvue is liable, not whether acetaminophen causes autism from a scientific standpoint. MedicalDaily will report on significant developments in the litigation and on any changes to medical guidance from ACOG, AAP, or FDA related to prenatal acetaminophen use.
The Bottom Line
A federal appeals court ruled that expert witnesses in the Tylenol autism lawsuits were improperly excluded, reviving more than 500 cases against Kenvue. That procedural ruling does not mean Tylenol has been found to cause autism. The scientific and medical consensus, supported by the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, and other major medical organizations, remains that there is no proven causal link, and that acetaminophen at recommended doses remains the appropriate first-line treatment for fever and pain during pregnancy. Pregnant people with questions should speak with their health care provider, not change their medication based on a legal headline.
