Penile anthropometry in Brazilian children and adolescents.

OBJECTIVE Classically, the penis has two functions: to make internal fertilization possible and to direct the urine stream. However, objective abnormalities in penis size can lead to diseases being diagnosed. Furthermore, many medical consultations are the result of patients seeking parameters for normal penis size. Additionally, the penile anthropometry of Brazilian children and adolescents has not yet been properly studied. The objective of this study is to carry out penile anthropometry of Brazilian children and adolescents, establishing references for clinical use. METHODS A cross-sectional study was carried out of 2,010 patients with ages varying from 0 to 18 years. Five penile measurements were taken: diameter of penile shaft; apparent and real length of flaccid penis; apparent and real (RSL(max)) length of flaccid penis fully stretched. Pubertal development was defined according to Tanner's criteria. RESULTS Only RSLmax, out of all of the penile measurements, did not exhibit significant interobserver variation at all ages analyzed (p = 0.255). Results were tabulated with mean RSLmax and the values that define micropenis (mean - 2.5 standard deviations) by age and by Tanner sexual maturity stages. A graph was plotted of the distribution of RSLmax results by the 10th, 25th, 50th, 75th and 90th percentiles and by age. CONCLUSIONS Out of all of the penile anthropometric measurements, only RSL(max) is clinically useful. We recommend our results as a reference standard for penile anthropometry of Brazilian children and adolescents.