Urinary Tract Infections (UTIs)
Among the few alleged benefits of circumcision that are of actual relevance to children, the most prominent is the claim that it protects against urinary tract infections in the first year of life. The degree of relative risk reduction for circumcised boys is most often reported as 10-fold (over a small absolute incidence), based on retrospective data. However, a large prospective cohort study – a more reliable research design – reported a relative risk reduction in hospitalization for UTI of 3.7-fold. Furthermore, in this study, when all outpatient UTIs were considered, the relative risk reduction dropped to 1.73-fold.
To put UTIs into perspective, a study from Sweden, where boys are not circumcised, found that, over the first six years of life, the absolute risk of UTIs in boys was low, at 1.8% versus 6.6% in girls, and that UTI infection in boys was rare after the first year of life (0.1-0.2%). Another investigator found a UTI rate of 0.08% in males >1 year old. When UTIs do occur, they respond rapidly to antibiotic therapy.[26-28] UTIs in the first months of life are less likely to involve the kidneys, and UTIs rarely, if ever, result in hypertension or end-stage kidney disease.[30-37]
Nonetheless, UTIs have been touted as a “compelling” reason for circumcision largely due to the efforts of Thomas Wiswell who, beginning in 1982, searched U.S. Army hospital databases to compare UTI rates in circumcised and intact infant males.[38, and others] The American Academy of Pediatrics itself critiqued the spate of studies produced by Wiswell and other investigators around the same time, stating,
- It should be noted that these studies were retrospective in design and may have methodological flaws. For example, they do not include all boys born in any single cohort or those treated as outpatients, so the study population may have been influenced by selection bias.
In addition, these studies failed to control for potentially confounding factors, such as being born prematurely. Prematurity puts babies at higher risk of infections of all kinds due to their immature immune systems, and such infants are more likely to undergo catheterization for various reasons, in itself increasing the infection risk. However, premature babies are also typically not circumcised because of their fragile medical condition, thus prematurity itself (rather than the presence of a foreskin) could explain the higher rate of UTIs found in intact infants.
There are no studies on circumcision and UTI that have adjusted for the various possible confounding factors. One statistical analysis modeled the impact of confounders on rates of diagnosis of UTIs, starting from the hypothetical assumption of no actual difference in UTIs between circumcised and intact boys. Documented confounders accounted for in the model included prematurity, method of urine collection (the commonly used bag method produces more false positives in intact boys), differential health-seeking behavior (parents of prematurely born [thus more often intact] babies, and of typically non-circumcised Hispanic boys, have been shown to disproportionately seek medical care for minor medical problems), and differential rates of UTI testing of intact boys (due to clinicians’ assumptions of their increased risk), among others. The model determined that, if there were no real difference in the rate of UTIs, intact boys would be diagnosed with a UTI 4.27 times more often than circumcised boys due to such confounding factors alone. The author concluded that “it is quite possible that the differences noted in the incidence of urinary tract infection between circumcised and non-circumcised boys are entirely due to confounding factors.”
In particular, no study has ever adjusted for the effect of forcible foreskin retraction, a common injury that was once standard medical ‘care’ based on North American clinicians’ lack of understanding of normal foreskin development.[41,42] Although the American Academy of Pediatrics has recommended against the practice of forced foreskin retraction for decades, it persists both in clinical settings and at home by parents, due to erroneous and aggressive hygiene advice. Traumatic retraction is invariably performed without any antisepsis, putting intact boys at risk of iatrogenic (doctor-caused) UTI, and potentially biasing studies of UTI incidence.
On the other hand, a number of other studies have failed to find a UTI risk-reduction effect from circumcision.
For example, eight studies from Israel demonstrated, in fact, the opposite: a positive association between ritual circumcision on the eighth day and immediate post-circumcision UTI.[43-50]
Mueller et al. conducted in a prospective study of 108 male infants under 6 months of age with UTI. They found that, regardless of circumcision status, infants who presented with their first UTI at 6 months or less were likely to have an underlying GU abnormality (~75%), mostly vesicoureteral reflux (backward flow of urine from the bladder to the kidneys, which can carry pathogens upstream in the urinary tract), and that in the remaining boys with UTI who had normal anatomy, circumcised and intact boys were equally represented. Thus, the presence of anatomical abnormalities, not the foreskin, was found to be the predominant associated risk factor of the UTIs.
Kwak et al. studied whether circumcision during surgery to correct vesicoureteral reflux made a difference in the incidence of post-operative UTI. Over 12 years of follow-up, the authors found no difference in number of post-operative UTI episodes between boys circumcised during antireflux surgery and those that were not. Again, the presence of the foreskin was not a factor.
Even if the earlier studies are accurate, it is estimated that between 111 and 195 circumcisions would be needed to prevent one urinary tract infection.[22,23] Since circumcisions cost at least $285 each, it would be necessary to spend between $31,635 and $55,575 to prevent a single infection with no long-term consequences, and that infection can easily be treated with an oral antibiotic that costs less than $20. It has been estimated that only one boy in 6000 will legitimately require a circumcision related to difficulties from UTIs.
The evidence suggests that circumcision is, at best, of little value in reducing UTI. Risks, complications, and disadvantages of circumcision outweigh any reduction in UTI.[55-57] Breastfeeding has a protective effect against infection in infancy, including UTI,[58-61] an effect that continues even after weaning.[58,59] Instead of circumcision, breastfeeding[62,63] and rooming-in (to colonize the infant with maternal bacteria) are recommended to reduce UTI in infancy.