University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• In boys up to 5 years old, does circumcision decrease the incidence of symptomatic urinary tract infections?

Clinical Bottom Lines

1. The absolute risk of developing a UTI in all young boys, circumcised or uncircumcised, is low (at most 1%).¹
2. Randomized, controlled trial data is not available regarding the question of circumcision and risk of UTI; we rely instead on retrospective reviews, cohort studies, and case control studies for evidence on this topic.
3. The available studies examining this issue support an association between circumcision status and risk of UTI.^1-4
4. The study summarized demonstrated a decreased risk of symptomatic UTI in circumcised preschool boys compared to uncircumcised preschool boys. This effect is independent of age when stratified into under- and over- one year old groups.

Summary of Key Evidence

1. This was a case control study in which 144 boys less than 5 years old with culture-proven UTI were enrolled as case subjects between 3/1/93 and 12/17/94 at a large ambulatory pediatric center in Sydney, Australia. 742 boys less than 5 years old without symptomatic UTI were enrolled as control subjects between 4/5/95 and 5/2/95 at the same pediatric center.⁴
2. 2 of the 144 patients with UTI (1.4%) were circumcised compared with 47 of 742 control patients (6.3%). This represented a significant difference in incidence of circumcision between the groups (p=0.02, OR 0.21, 95% CI 0.06-0.76).
3. Case patients had a significantly lower median age (5.8 months) than control patients (21.0 months). There was no evidence of an association between age and circumcision status among control patients.
4. When stratified by age group, 2 of 110 boys under 1 year old with UTI were circumcised vs. 16 of 231 boys under 1 year old without UTI (p=0.05, OR 0.03). 0 of 34 boys at least 1 year old with UTI were circumcised vs. 31 of 511 boys at least 1 year old without UTI (p=0.1, OR 0.2). Combined OR = 0.18, p=0.01.
   

Additional Comments

• A biological explanation for the association between intact foreskin and UTI has been put forth. Uropathogens appear to bind more avidly to the mucosal surface of the foreskin than they bind to stratified squamous epithelium.⁵ Uncircumcised boys may have higher rates of periurethral colonization with uropathogens than circumcised boys.⁶
• Potential confounding variables such as socioeconomic status, gestational age at birth, duration of breastfeeding, and race were not addressed in this study.
• There is also the potential for detection bias
• Parents must weigh many factors in their decision regarding circumcision for a child, including religious views, immediate risks of the procedure, psychological well-being, future risk of STD, as well as risk of UTI.
  

Citation

1. AAP Circumcision Policy Statement (RE9850). Pediatrics 1999; 103.
2. Wiswell et al. Decreased incidence of urinary tract infections in circumcised male infants. Pediatrics 1985; 75:901-3.
3. Wiswell et al. Risks from circumcision during the first month of life compared with those for uncircumcised boys. Pediatrics 1989;83:1011-5.
4. Craig et al. Effect of circumcision on incidence of urinary tract infection in preschool boys. Journal of Pediatrics 1996;128.
5. Fussell et al. Adherence of bacteria to human foreskins. Journal of Urology 1988;140:997-1001.
6. Glennon et al. Circumcision and periurethral carriage of Proteus mirabilis in boys. Archives of Disease in Children 1988;63;556-7.

CAT Author: Kimberly Yee, MD

CAT Appraisers: Ken Pituch, MD

Date appraised: December 17, 2003