Neonatal circumcision remains a controversial procedure when it is performed for reasons other than religious belief. Among the medical benefits cited is a reduction in urinary tract infections (UTIs) in infant boys following circumcision. To and colleagues studied Canadian boys from birth to three years of age to assess the relationship between UTIs and circumcision.

All singleton boys born to residents of Ontario during 1993, excluding those who were circumcised after the first month of life, were included in the study. Of the 69,100 boys, 30,105 (43.6 percent) were circumcised and 38,995 were uncircumcised. No infant had signs of urinary tract infection before the procedure.

The boys were followed for three years, during which time 83 circumcised boys and 247 uncircumcised boys were admitted to a hospital for UTI. Over 90 percent of these infants were admitted only once for UTI. The cumulative rate of hospital admissions for UTI was 1.88 per 1,000 in circumcised boys and 7.02 per 1,000 in uncircumcised boys by the end of the first year. The comparable figures at three years were 2.96 for circumcised boys and 8.75 for uncircumcised boys. The authors calculate the relative risk of hospital admission for uncircumcised boys as 3.0 during the first year of life. When data from out-patient billings for UTI in boys younger than three years were included in the calculations, the relative risk of UTI in uncircumcised boys fell to 1.73.

The authors conclude that previous studies have overestimated the risk of UTI in uncircumcised male infants. Although the rate of UTI is slightly increased in uncircumcised boys, UTI is rare, occurring in less than 1 percent of boys under one year of age. Approximately 195 circumcisions would need to be performed to prevent one hospital admission for UTI.