Does Newborn Circumcision Increase Autism Risk?

A large U.S. cohort study found no association between neonatal medical circumcision and autism spectrum disorder or autism-related traits.

Parents have long wondered whether newborn circumcision could increase a child’s risk of autism, especially after earlier studies sparked debate and social media discussions. Now, one of the largest U.S. studies to investigate this question offers reassuring evidence.
Researchers analyzed data from 2,771 boys enrolled across 14 sites in the National Institutes of Health-funded Environmental Influences on Child Health Outcomes (ECHO) Cohort and found that neonatal medical male circumcision (NMC) was not associated with autism spectrum disorder (ASD) or autism-related traits and behaviors after accounting for important health and family factors (1^✔ ✔Trusted Source
Neonatal Medical Male Circumcision and Child Autism Diagnosis

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). The findings help answer a long-debated question and allow families to make decisions based on high-quality scientific evidence rather than speculation.

Autism spectrum disorder (ASD) is a neurodevelopmental condition that affects how a person communicates, interacts socially, and processes the world around them. Scientists believe autism develops through a complex interaction of genetic and environmental factors rather than a single cause. Because newborn circumcision is one of the most commonly performed medical procedures in male infants, researchers wanted to determine whether it had any measurable association with later autism diagnosis or autism-related characteristics.

What Did the Study Find?

Researchers conducted a large prospective multicenter cohort study using data from the National Institutes of Health (NIH)-funded Environmental Influences on Child Health Outcomes (ECHO) Cohort, one of the largest child health research initiatives in the United States. The study included male singleton children with documented newborn circumcision status and validated developmental assessments collected between 2003 and 2025. Statistical analyses were performed between November 2025 and February 2026, and the study followed the internationally recognized STROBE reporting guideline for observational research.

Among the 2,771 boys included in the analysis, 1,840 (66%) underwent neonatal medical circumcision before hospital discharge, while 931 (34%) did not. Overall, 192 children (7%) were diagnosed with autism spectrum disorder, with the average age at diagnosis being 3.8 years.

After adjusting for factors known to influence autism risk, including maternal education, parental age, family history of autism, and geographic region, researchers found no significant association between neonatal circumcision and autism diagnosis (adjusted odds ratio 0.83; 95% confidence interval 0.59–1.17). The investigators also evaluated autism-related traits using two internationally validated developmental assessment tools, the Social Responsiveness Scale (SRS-2) and the Child Behavior Checklist (CBCL). Neither assessment showed evidence that newborn circumcision increased autism-related traits or behaviors.

How Researchers Evaluated Autism Risk

One of the major strengths of this research is that it went beyond simply comparing autism diagnoses. The investigators used standardized developmental assessments that measure social communication, repetitive behaviors, and other characteristics commonly associated with autism. This approach allowed researchers to evaluate both diagnosed autism and autism-related traits using well-established clinical tools.

The researchers also tested whether the findings remained consistent in different groups of children. They performed analyses according to geographic region, preterm birth, and neonatal intensive care unit (NICU) admission. Across these analyses, the overall conclusion remained unchanged, increasing confidence that the results were not driven by a specific subgroup.

Another concern raised in earlier discussions was whether acetaminophen given during or shortly after circumcision might influence neurodevelopment. In this study, acetaminophen use during the circumcision procedure or within the neonatal period was uncommon, occurring in fewer than 5% of children. Because its use was infrequent, the researchers concluded that an acetaminophen-mediated explanation was unlikely to account for autism risk in this cohort.

In addition, several sensitivity analyses, including leave-one-out analyses that excluded one study site at a time, produced similar results. This suggests that no single research center disproportionately influenced the overall findings, further strengthening confidence in the study conclusions.

Why Earlier Circumcision and Autism Studies Reached Different Conclusions

The possible relationship between circumcision and autism has been debated for more than a decade because previous observational studies reported conflicting findings. One ecological study suggested a correlation between circumcision rates and autism prevalence, while a Danish registry study reported a higher autism risk among circumcised boys. However, both studies had important methodological limitations, including differences in healthcare systems, diagnostic practices, exposure classification, and the possibility of residual confounding.

In contrast, the present study included detailed clinical information from a large and geographically diverse U.S. cohort while adjusting for multiple factors already known to influence autism risk. Although observational studies cannot prove cause and effect, the consistency of these findings across several analyses provides reassuring evidence that newborn medical circumcision is not associated with autism spectrum disorder or autism-related behaviors.

What This Research Means for Parents Considering Circumcision

For many parents, the decision to circumcise a newborn is influenced by cultural, religious, personal, and medical considerations. Concerns about possible long-term effects, including autism, have added uncertainty for some families. This study provides reassuring evidence that neonatal medical male circumcision was not associated with an increased likelihood of autism spectrum disorder or autism-related traits in this large and diverse U.S. cohort.

The authors emphasized that this was an observational cohort study, which means it can identify associations but cannot prove cause and effect. However, the findings remained consistent after adjustment for important confounding factors and across multiple subgroup and sensitivity analyses, strengthening confidence in the overall conclusion.

The researchers also acknowledged several limitations. The study evaluated only hospital-based neonatal circumcision, so the findings may not apply to circumcisions performed later in childhood or outside healthcare settings. Information on insurance status was limited, which means some residual confounding may still exist. In addition, although the study included participants from 14 sites across the United States, it does not represent every newborn male in the country. These limitations highlight why continued research remains important even when findings are reassuring.

Key Evidence From the Study

What Parents Can Take Away From This Study

This study adds reassuring evidence for families considering newborn circumcision. While no single study can answer every scientific question, these findings suggest that autism should not be a deciding factor when making circumcision-related decisions. Parents should continue relying on healthcare professionals and evidence-based information when discussing their child’s care.

Bottom Line

New research often raises important questions for parents, especially when it involves common childhood procedures and long-term health. This large U.S. study adds reassuring evidence that newborn medical circumcision was not associated with autism spectrum disorder or autism-related behaviors. While researchers will continue investigating the many genetic and environmental factors involved in autism, the current findings suggest that concerns about autism should not drive decisions about newborn circumcision.

Parents should continue discussing the potential benefits and risks of circumcision with their healthcare provider while following routine developmental check-ups recommended for every child. If there are concerns about a child’s communication, behavior, or development, seeking an early medical evaluation remains the best course of action, regardless of circumcision status.

As more high-quality research becomes available, studies like this help separate scientific evidence from long-standing misconceptions, enabling families to make informed healthcare decisions with greater confidence.

References:

1. Neonatal Medical Male Circumcision and Child Autism Diagnosis – (https://jamanetwork.com/journals/jamapediatrics/fullarticle/2852526)
2. Neonatal Medical Male Circumcision and Child Autism Diagnosis – (https://pubmed.ncbi.nlm.nih.gov/42545713/)
3. Autism Spectrum Disorder (ASD) – (https://www.cdc.gov/autism/)

Source-Medindia