Makari (FDA head) is quoted as saying that a collection of studies, including from the Boston Birth Cohort, the Nurses Health Study and Mount Sinai-Harvard have established that there is a "causal relationship between prenatal acetaminophen use and neurodevelopmental disorders of ADHD and autism spectrum disorder." Does the evidence support this?
Short answer: No. The FDA itself is not saying the link is causal. In fact, in the FDA’s own physician notice released alongside the White House messaging, the agency states plainly: “a causal relationship has not been established” (their emphasis). 
Here’s the quick evidence check:
• What FDA actually did/says: FDA began a process to consider label changes noting a possible association between prenatal acetaminophen use and later neurodevelopmental diagnoses, and it sent doctors a notice. But the agency’s language is careful: association ≠ causation, and it explicitly says causality hasn’t been shown. 
• Makary’s claim of a “causal relationship”: That overstates the literature. Studies he cites (e.g., the Boston Birth Cohort/JAMA Psychiatry cord-biomarker analysis) report associations—including dose-response patterns—but they are observational and susceptible to confounding (indication for use, familial and genetic factors, measurement error). They do not prove causation. 
• Highest-quality counter-evidence: Large, family-based designs that control for shared genetics and environment (e.g., a 2024 nationwide Swedish cohort in JAMA) do not find evidence of a causal link once those factors are accounted for. Professional groups have leaned on this kind of evidence in their responses. 
• Professional guidance right now:
• The American College of Obstetricians and Gynecologists (ACOG) called the new government messaging not backed by the full body of evidence and reiterated that no reputable study has proven acetaminophen in pregnancy causes ASD/ADHD. 
• The Society for Maternal-Fetal Medicine (SMFM) likewise continues to advise that acetaminophen is appropriate when clinically indicated during pregnancy. 
• Media framing vs. documents: Some coverage and quotes may imply the “head of FDA” endorsed causality, but the agency’s own notice contradicts that. If you’re seeing headlines or TV segments asserting “causal,” they’re out over their skis relative to the FDA’s written position. 
• Mount Sinai/Harvard items: Recent institutional communications and reviews from that collaboration say “may be linked” and call for cautious, time-limited use and more research—not that causality has been proven. 
Bottom line: Evidence is mixed and mostly observational; causation hasn’t been demonstrated. FDA’s official documents say so, and leading OB societies agree. If you want, I can walk through the specific studies Makary named (Boston Birth Cohort, Nurses’ Health Study, Mount Sinai/Harvard) and show exactly what each did—and didn’t—conclude. 
