The aim of this study was to establish a normal range of preterm and term stretched penile length based on their gestational age and anthropometric parameters at birth. A total of 585 infants; 336 (57.43%) preterm and 249 (42.57%) term male infants born between August 2015 and September 2016 with gestational age between 26 and 41 weeks were included in our study. Stretched penile length was measured from the pubic ramus to the tip of the glans. Gestational age, stretched penile length and anthropometric parameters at birth (weight, length and head circumference) were recorded within the first three days of life. Variations of stretched penile length in relation to gestational age and anthropometric parameters were evaluated using multiple linear regression models. The mean stretched penile length ± SD of preterm and term neonates were 2.5±0.565 cm and 3.2±0.551cm, respectively. In all infants, stretched penile length was significantly affected by gestational age and birth length (OR: 0.079, 95% CI 0.059-0.098, p=0.0001, OR:0.022, 95% CI 0.007-0.037, p=0.005, respectively). In term infants, stretched penile length was significantly affected by gestational age (OR: 0.139, 95% CI 0.082-0.196, p=0.0001) and in preterm infants, gestational age and birth length significantly infleuenced the stretched penile length (OR: 0.090, 95% CI 0.065-0.0115, p=0.0001, OR:0.024, 95% CI 0.009-0.039, p=0.002, respectively). This study provides reference values of stretched penile length for term and viable preterm Turkish infants.

Keywords: Turkish, preterm infants, stretched penile length, term infants