Is there a difference in the rate of autism spectrum disorder (ASD) between circumcised and uncircumcised children?

Circumcision and Autism Spectrum Disorder: Evidence Review

There is insufficient evidence to establish a causal relationship between circumcision and autism spectrum disorder (ASD), and current clinical guidelines do not recognize circumcision as a significant risk factor for ASD development.

Current Understanding of ASD Etiology

• ASD has a complex, multifactorial etiology with strong genetic components and potential environmental factors, as recognized by major medical organizations 1, 2
• Genetic factors are the most significant contributors to ASD risk, with high recurrence risk in siblings (2-10%) and higher concordance in monozygotic twins (70-90%) compared to dizygotic twins (3%) 1, 3
• ASD prevalence has increased significantly over time, with current estimates at approximately one in 36 children in the United States (2.8%), representing a quadrupling in prevalence over the past two decades 4, 5
• Males are diagnosed with ASD 3-4 times more frequently than females, with current estimates showing ASD is 3.8 times more prevalent among boys than girls 1, 4

Evidence Regarding Circumcision and ASD

• One Danish cohort study found that circumcised boys were more likely than intact boys to develop ASD before age 10 years (HR = 1.46; 95% CI: 1.11-1.93), with particularly high risk for infantile autism before age five years (HR = 2.06; 95% CI: 1.36-3.13) 6

• However, this single study has several limitations:

  • It represents an ecological association rather than proven causation 6
  • The study did not control for all potential confounding variables 6
  • The findings have not been replicated in other large-scale studies 2

• Clinical genetics evaluation guidelines from the American College of Medical Genetics do not list circumcision among factors to consider when identifying the etiology of ASD 2, 3

• The American Academy of Child and Adolescent Psychiatry's practice parameters for ASD do not mention circumcision as a risk factor 2, 3

Established Risk Factors for ASD

• Advanced maternal and paternal age significantly increases ASD risk 1, 2
• Extremely premature birth (<26 weeks' gestational age) increases ASD risk 1, 3
• Family history of learning/language problems and social disability are associated with increased ASD risk 1, 2
• Specific genetic mutations and chromosomal abnormalities account for approximately 40% of ASD cases 1, 3
• Environmental exposures to certain chemicals during prenatal development may contribute to ASD risk 1

Clinical Implications

• Standard evaluation for children with ASD should focus on established genetic and environmental factors rather than history of circumcision 2, 3
• Comprehensive genetic evaluation remains the standard of care for identifying potential etiologies of ASD 3
• Early identification and intervention for ASD should be prioritized regardless of circumcision status, as early intervention improves outcomes 5

Limitations and Considerations

• The single study showing association between circumcision and ASD 6 requires replication in other populations before clinical recommendations can be made
• Correlation does not imply causation, and the observed association may be due to other factors not accounted for in the study design 7
• Current clinical guidelines from major medical organizations do not recognize circumcision as a risk factor for ASD 2, 3

In conclusion, while one study has suggested a potential association between circumcision and ASD risk, this finding has not been incorporated into clinical guidelines, and the current consensus focuses on established genetic and environmental risk factors for ASD diagnosis and management.