Cross-Sectional Analysis of Penile Length in Males 13 to 15 Years Old According to Pubertal Development Stages

Abstract

Genital development is affected by pubertal process to a great extent, and puberty is a complex phenomenon that is influenced by multiple factors resulting in individual differences. We studied penile length and its relationship to pubertal stage in boys 13 to 15 years old. Healthy boys who were candidates for military high school were evaluated between June and July 2011. Age, residence and body mass index were recorded. Stretched penile length was measured. Pubic hair was assessed according to Tanner and Marshall staging. Genital puberty stage was defined by measurement of testicular volume with Prader orchidometer. Relationship of penile length to age, residence, pubertal stages and body mass index was evaluated statistically. A total of 1,539 boys were included in the study. Mean ages and number of patients according to genital stage were as follows. Mean age was 14 years for genital stage 1 (5 patients), 13.9 years (range 13 to 15) for stage 2 (194), 14.07 years (13 to 15) for stage 3 (965) and 14.11 years (13 to 15) for stage 4 (375). Linear regression analysis revealed a significant effect of body mass index, genital stage and pubic hair stage on penile length (p <0.001) but no significant effect of age or residence. Mean penile length was significantly different among different age groups and among pubertal stages. However, mean penile lengths of different age groups within the same pubertal stage were similar. Penile length during puberty should be evaluated individually according to the current pubertal stage. Our study offers a reliable reference table of penile length for pubertal age group.