This prospective cohort study (ECHO Cohort, 2003–2025) examined whether neonatal medical male circumcision (NMC) within 28 days of birth was associated with ASD diagnosis or autism-related traits in 2,771 male singleton children across 14 US sites.
No association was found between NMC and ASD diagnosis after adjusting for confounders (OR 0.83; 95% CI 0.59–1.17). Circumcised boys had a lower raw rate of autism (6%, 108/1,840) vs. uncircumcised boys (9%, 84/931), but this difference did not persist in adjusted models. No associations were found for autism-related traits (SRS-2) or behaviors (CBCL 1.5/5) either.
- ASD diagnosis relied partly on parent-reported medical professional diagnosis, not solely criterion-standard clinical assessments. - Acetaminophen use data were only available for a subset, limiting analysis of that potential confounder. - Observational design cannot fully exclude residual confounding (e.g., by socioeconomic or cultural factors correlated with circumcision rates).
Clinicians and families can be reassured that neonatal medical circumcision is not associated with increased autism risk based on this large, multi-site prospective cohort. This evidence directly counters widespread public speculation about an NMC–ASD link.
