A federal appeals court on Monday, July 13, 2026, revived more than 500 lawsuits that allege Tylenol and generic acetaminophen can cause autism or attention-deficit/hyperactivity disorder if used during pregnancy.
The decision sends the cases back toward further proceedings, but the practical caveat is just as important as the headline: the ruling does not find that acetaminophen causes autism or ADHD, and it does not change medical advice by itself.
What changed
The Second U.S. Circuit Court of Appeals in Manhattan ruled that the trial judge had erred when excluding expert medical witnesses offered by the plaintiffs, according to The Wall Street Journal. Those witnesses were expected to support the plaintiffs' argument that prenatal acetaminophen exposure can be linked to neurodevelopmental disorders.
The litigation is part of a multidistrict case in the Southern District of New York. The court's MDL page says the plaintiffs assert that children developed autism spectrum disorder or ADHD as a result of in utero exposure to acetaminophen, and it lists earlier orders that excluded plaintiffs' expert opinions in 2023 and 2024.
What the ruling does not say
Kenvue, the consumer-health company behind Tylenol, said the appeals decision was procedural and that it is exploring its options. The company said the ruling gives it another chance to challenge the plaintiffs' experts and said it continues to stand behind the product's safety.
That distinction matters because legal admissibility and medical proof are different questions. The FDA said in September 2025 that some studies have described an association between acetaminophen use during pregnancy and later autism or ADHD diagnoses, but it also said a causal relationship has not been established and that contrary studies exist.
One major 2024 JAMA study followed more than 2.4 million children in Sweden. Its sibling-control analysis found no evidence of increased autism, ADHD or intellectual-disability risk associated with acetaminophen use during pregnancy, suggesting that earlier associations may have reflected family or health factors rather than the medicine itself.
What to do now
For families, the safest reading is narrow: the lawsuits are alive again, not proven. Pregnant readers or anyone planning a pregnancy should treat the court ruling as legal news, not as individual medical guidance.
Anyone weighing pain or fever treatment during pregnancy should talk with a clinician who knows their health history. Untreated fever can carry risks, and medication decisions depend on dose, timing, symptoms and alternatives. The next legal step is back in federal court, where expert testimony and evidence will be tested again.
