Analysis of shape and retractability of the prepuce in 603 Japanese boys

Purpose: We evaluated preputial development in Japanese boys. Materials and Methods: Preputial retractability and formation of a tight ring were evaluated in 603 Japanese boys 0 to 15 years old. Results: The incidence of a completely retractable prepuce gradually increased from 0% at age 6 months to 62.9% by 11 to 15 years, while that of a tight ring decreased with age from 84.3 to 8.6%. Nine boys had balanoposthitis but none had a symptomatic urinary tract infection. Conclusions: Incomplete separation of the prepuce is common and normal in neonates and infants, and preputial separation progresses until adolescence. Awareness of these findings will eliminate unnecessary circumcision in boys.