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Letters
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published in print.
‘Circumcision pain’ unlikely to cause
autism
Claims by Frisch and Simonsen
1
that ‘circumcision
pain’ increases risk of autism spectrum disorder are
flawed. They dredged Danish medical records of
342,877 boys aged 0–10 years looking for an adverse
effect of circumcision. Marginal significance was
apparent for autism spectrum disorder at age
0–4 years for 28 Muslim boys circumcised before
the age of 2 years. Since HR was 1.54 (95% CI,
1.03–2.31), the circumcision effect involved approxi-
mately 10 boys. In 0–4-year-old circumcised non-
Muslim boys they noted six autism spectrum disorder
diagnoses and three hyperkinetic disorder diagnoses.
Of 337 Muslim boys aged 0–10 years with autism
spectrum disorder, only 10.9% were ‘circumcised’,
89.1% being ‘intact’, which is improbable and under-
mines their findings.
The authors cite a survey that found pain was high
in 4% of infants during six weeks post-circumcision.
Since the Danish study was about pain why didn’t
Frisch and Simonsen examine other painful condi-
tions? Urinary tract infections are associated with
excruciating pain, are common and very much
higher in uncircumcised male infants and boys.
2
If
the authors’ pain hypothesis were correct, then
autism spectrum disorder should be associated with
urinary tract infections and therefore being
uncircumcised.
Anaesthetics are neurotoxic to the developing
brain. Systemic use in children aged under 3 years is
associated with later cognitive impairment.
3
Could
unnecessary general anaesthesia, not pain, have con-
tributed to autism spectrum disorder?
They cite a study correlating autism spectrum dis-
order and circumcision prevalence post-1995, but fail
to state that this was actually a study of paracetamol
usage, circumcisions being merely a proxy.
4
That
‘hypothesis generating exploratory analysis’ was
prompted by the difference in paracetamol metabol-
ism in immature brains that might produce neuronal
damage in susceptible infants.
Most likely, both autism spectrum disorder diag-
nosis and early circumcision reflect parental
conscientiousness.
Declarations
Competing interests: None declared
References
1. Frisch M and Simonsen J. Ritual circumcision and risk
of autism spectrum disorder in 0- to 9-year old boys:
national cohort study in Denmark. J R Soc Med 2015;
Epub ahead of print Jan 8, 2015:doi:10.1177/
0141076814565942.
2. Morris BJ and Wiswell TE. Circumcision and lifetime
risk of urinary tract infections: A systematic review and
meta-analysis. J Urol 2013; 189: 2118–2124.
3. Ing C, DiMaggio C, Whitehouse A, Hegarty MK,
Brady J, von Ungern-Sternberg BS, et al. Long-term
differences in language and cognitive function after
childhood exposure to anesthesia. Pediatrics 2012;
130: e476–e85.
4. Bauer AZ and Kriebel D. Prenatal and perinatal anal-
gesic exposure and autism: an ecological link. Environ
Health 2013; 12: 41.
Brian J Morris
School of Medical Sciences, University of Sydney, Sydney,
New South Wales, Australia
Email: brian.morris@sydney.edu.au
Thomas E Wiswell
Center for Neonatal Care, Florida Hospital, Orlando, FL, USA
Circumcision-autism link needs
thorough evaluation: Response to
Morris and Wiswell
Morris and Wiswell express concern over small num-
bers of circumcised boys with autism spectrum dis-
order (ASD) and hyperkinetic disorder in non-
Muslim families, apparently unaware of the fact
that our findings were statistically significant despite
the limited statistical power of these analyses, not
because of it. Also, without substantiation, our critics
consider the overall proportion of boys in Muslim
families who were ritually circumcised by Danish
doctors (10.9%) ‘improbable’, although no one
knows the exact proportions of ritual circumcisions
Journal of the Royal Society of Medicine; 2015, Vol. 108(8) 297–298
DOI: 10.1177/0141076815590404
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