title: Penile length, digit length, and anogenital distance according to birth weight in newborn male infants.
abstract: OBJECTIVE
  Anogential distance (AGD) and the 2:4 digit length ratio appear to provide a reliable guide to fetal androgen exposure. We intended to investigate the current status of penile size and the relationship between penile length and AGD or digit length according to birth weight in Korean newborn infants.
  
  
  METHODS
  Between May 2013 and February 2014, among a total of 78 newborn male infants, 55 infants were prospectively included in this study. Newborn male infants with a gestational age of 38 to 42 weeks and birth weight>2.5 kg were assigned to the NW group (n=24) and those with a gestational age<38 weeks and birth weight<2.5 kg were assigned to the LW group (n=31). Penile size and other variables were compared between the two groups.
  
  
  RESULTS
  Stretched penile length of the NW group was 3.3 ± 0.2 cm, which did not differ significantly from that reported in 1987. All parameters including height, weight, penile length, testicular size, AGD, and digit length were significantly lower in the LW group than in the NW group. However, there were no significant differences in AGD ratio or 2:4 digit length ratio between the two groups.
  
  
  CONCLUSIONS
  The penile length of newborn infants has not changed over the last quarter century in Korea. With normal penile appearance, the AGD ratio and 2:4 digit length ratio are consistent irrespective of birth weight, whereas AGD, digit length, and penile length are significantly smaller in newborns with low birth weight.
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Gina
authors.initials: G
authors.lastname: Lim
authors.affiliation: Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Oh
authors.affiliation: Department of Urology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Ryu
authors.affiliation: School of Mechanical Engineering, Pusan National University, Busan, Korea.
authors.forename: Seonghun
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Jeon
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Sang Hyeon
authors.initials: SH
authors.lastname: Cheon
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Moon
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Sejun
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Urology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea.
authors.forename: Sungchan
authors.initials: S
authors.lastname: Park
mesh_terms: D000886:Anthropometry; D001724:Birth Weight; D001837:Body Weights and Measures; D003430:Cross-Sectional Studies; D005385:Fingers / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D009929:Organ Size; D010413:Penis / Q000033:anatomy & histology*; D056910:Republic of Korea
keywords: Anthropometry; Newborn infants; Penis