A federal appeals court has revived hundreds of lawsuits linking acetaminophen (Tylenol) use during pregnancy to autism and ADHD in children. The decision overturns a district court judge's earlier dismissal based on concerns about scientific reliability.
The appellate panel determined that plaintiffs could proceed with cases alleging acetaminophen exposure in utero contributed to neurodevelopmental disorders. This reversal allows the litigation to move forward despite the district judge's initial finding that the evidence supporting the connection lacked sufficient scientific foundation.
The ruling reflects ongoing tension between epidemiological research and legal standards for evidence. Multiple observational studies have suggested associations between prenatal acetaminophen use and autism spectrum disorder or attention-deficit hyperactivity disorder. A 2016 study published in JAMA Pediatrics found increased odds of ADHD among children whose mothers used acetaminophen during pregnancy. However, these studies cannot prove causation, and the FDA has not changed its guidance on acetaminophen safety in pregnancy.
Acetaminophen remains one of the most commonly used over-the-counter pain relievers during pregnancy. Millions of pregnant people take it for headaches, fever, and general pain relief. Medical organizations including the American College of Obstetricians and Gynecologists have not recommended eliminating acetaminophen use in pregnancy, citing its long safety record.
The appeals court's decision allows plaintiffs to present their evidence to a jury, shifting the burden onto the scientific record itself. The cases will likely examine whether the available studies establish sufficient causation for legal liability. Defense attorneys will argue that correlation studies cannot prove acetaminophen causes autism or ADHD, particularly given the complex, multifactorial nature of these conditions.
This litigation echoes previous product liability cases involving pregnancy exposures. The outcome could influence how courts evaluate epidemiological evidence in future