Flaccid penile length and stretch factor in the newborn

Objective: Little is known about the flaccid penile length in the newborn and the degree of stretch of the penis among investigators while measuring the stretched penile length. This study aimed to document the flaccid penile length and the stretch factor in the newborn.Methods: This cross-sectional study was carried out on 200 term male infants within the first 72 hours of life. The flaccid penile length and the stretched penile length were measured with a wooden spatula and the stretch factor was calculated.Results: The mean (±SD) flaccid and stretched penile length were 30.9 ± 3.8 mm and 38.9 ± 4.0 mm respectively. The mean stretch factor was 26.4 %. Both testes had the same mean volume of 1.6 ± 0.5 ml. There was a significant correlation between flaccid and stretched penile lengths (r = 0.775, p = 0.000). The flaccid penile length was a significant predictor of the stretched penile length.Conclusion: This study has been able to determine the stretch factor while measuring the flaccid and stretch penile lengths in Nigerian newborn infants. It is recommended that the flaccid penile length be measured along with the stretched penile length and determine the stretch factor in order to compare how much investigators stretch the penis during measurement. This will allow for detailed comparison of penile anthropometry across different ethnic groups and races. Keywords: flaccid penile length, newborn, stretch factor, stretched penile length.