Neonatal Medical Male Circumcision and Child Autism Diagnosis

Importance: Public concern and speculation have emerged around a possible link between neonatal male circumcision (NMC) and autism spectrum disorder (ASD). Evidence is limited and inconsistent. Objective: To examine associations between NMC and child ASD and autism-related traits and behaviors. Design, Setting, and Participants: This prospective cohort study was conducted among cohort sites participating in the Environmental Influences on Child Health Outcomes (ECHO) Cohort between February 2003 and September 2025. Statistical analyses were conducted from November 2025 to February 2026. The analysis included male, singleton children with data on NMC status and child ASD. Exposure: NMC status within 28 days of birth at a medical facility. Main outcomes and Measures: ASD diagnosis was based on parent report of diagnosis by a medical professional or documentation of criterion standard clinical assessments. Social Responsiveness Scale (SRS-2) T-scores assessed the presence and distribution of autism traits, and Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) Autism Spectrum Problems subscale T-scores from the Child Behavior Checklist (CBCL) 1.5/5 assessed the occurrence of child autism-related behaviors. Results: The sample included 2771 male children from 14 ECHO sites, of whom 1840 (66%) were circumcised before hospital discharge, and 192 (7%) had an autism diagnosis. Among 1840 circumcised males, 108 (6%) had autism, compared with 84 of 931 uncircumcised males (9%). Mean (SD) age at autism diagnosis was 3.8 (2.2) years. Among circumcised males, 31 (4%) were administered acetaminophen during the procedure, and 128 (7%) within the 30 days after birth. After adjusting for confounders, there was no association between NMC and ASD diagnosis (odds ratio [OR], 0.83; 95% CI, 0.59-1.17). After stratification by region, preterm birth, and neonatal intensive care unit admission, an inverse or no association was observed between NMC and ASD diagnosis. Adjusted analyses showed no associations between NMC and SRS-2 continuous (β = -0.62; 95% CI, -1.46 to 0.22) or binary (OR, 0.75; 95% CI, 0.48-1.15) T-scores. Similarly, no associations were observed between NMC and CBCL 1.5/5 continuous (β = 0.01; 95% CI, -0.54 to 0.56) or binary (OR, 1.30; 95% CI, 0.75-2.26) T-scores. Overall, inverse or no associations were observed across all strata for SRS-2 and CBCL 1.5/5 outcomes. Conclusions and Relevance: This cohort study yielded no evidence that NMC was associated with ASD risk, whether assessed by parent report of medical professional diagnosis or validated instruments measuring autism-related traits and behavior. These findings may provide reassurance for families who are considering or have elected NMC for their child.