Approximately 55 percent to 65 percent of all newborn boys are circumcised in the United States each year. Routine circumcision is usually performed during the first 10 days (often within the first 48 hours), either in the hospital or, for some religious ritual circumcisions, at home.
Conclusions are based on converging observations in animal, clinical and ecological studies, Dr. Morten Frisch, MD, PhD, DSc, consultant and senior investigator conducting epidemiological research at Statens Serum Institute. Adjunct professor of sexual health epidemiology at Aalborg University and lead author of this study along with Jacob Simonsen, Center for Sexology Research, Aalborg University, hypothesized a possible impact of ritual circumcision on the subsequent risk of autism spectrum disorder (ASD) in young boys.
This study included 342,877 boys born between 1994 and 2003 and followed through the age of nine, and during the course of the study.
During the course of the study 4.986 cases of autism were diagnosed. The study showed that regardless of cultural background, circumcised boys were more likely to develop autism. Being circumcised before age 10 was associated with a 46 percent increased risk but if circumcision took place before the age of five the risk doubled.
Circumcised boys in non-Muslim families were also more likely to develop hyperkinetic disorder by 81 percent.
Dr. Frisch stated “Our investigation was prompted by the combination of recent animal findings linking a single painful injury to lifelong deficits in stress response and a study showing a strong, positive correlation between a country’s neonatal male circumcision rate and its prevalence of ASD in boys.”
Today it is considered a medically unacceptable practice to circumcise boys without proper pain relief but none of the most common interventions used to reduce circumcision pain completely eliminates it. Some boys will endure intensely painful circumcisions. Researchers say that the pain associated with circumcision in very young babies is likely to be more severe during the operation and post-operatively.
Painful experiences in neonates have been shown in animal and human studies to be associated with long-term alterations in pain perception, a characteristic often encountered among children with ASD.
“Possible mechanisms linking early life pain and stress to an increased risk of neurodevelopmental, behavioral or psychological problems in later life remain incompletely conceptualized,” said Dr. Frisch, who continued, “Given the widespread practice of non-therapeutic circumcision in infancy and childhood around the world, our findings should prompt other researchers to examine the possibility that circumcision trauma in infancy or early childhood might carry an increased risk of serious neurodevelopmental and psychological consequences.”
There are experts, however, that are urging caution about this study.
Professor Jeremy Turk. MD, BSc (Hons), FRCPsych, FRCPCH, DCH, Consultant Child and Adolescent Psychiatrist in the Trust’s Behavioural Phenotype Learning Disabilities Service and a Professor of Developmental Psychiatry at the Institute of Psychiatry, related to the Daily Mail that while the findings of the study were “interesting,” they needed to be “considered carefully.”
“This is not a causal study, but instead compares data sets and looks for correlations. While this is a valid way of doing a study, it means that we must be careful about any implications,” he said. “For example, many cases of autism are missed until children are older and as there are relatively few cases of autism this could easily skew the data.”
“Furthermore, there are many potentially confounding variables which could explain raised ASD rates, which the authors do not explore or account for.”
“Finally, I have some issues with the premise in that their speculations regarding early pain as a cause of autism are, to say the least, highly speculative.”
Dr. Rosa Hoekstra, PhD, a lecturer in The Open University’s Science faculty, commented to the Daily Mail, “I think this is an extremely speculative study.” She related that the study is based on registered data, “and takes a registered autism diagnosis at face value, without considering cultural or social factors affecting the likelihood of an (early) autism diagnosis. Even in a high income country like Denmark, not all children with autism are detected and given a suitable autism diagnosis at an early age.”
Professor McConway, professor of applied statistics also with the Open University adds “This study raises an interesting question, but one that cannot be fully answered with these data.”
Ritual circumcision and risk of autism spectrum disorder in 0- to 9-year-old boys: national cohort study in Denmark. Journal of the Royal Society of Medicine, 2015; DOI: 10.1177/0141076814565942