title: Perineal body length among different racial groups in the first stage of labor.
abstract: OBJECTIVE
  Anatomic differences among racial groups may contribute to observed differences in the occurrence of severe perineal lacerations at the time of vaginal delivery. The purpose of this study was to identify differences in perineal body length between racial groups.
  
  
  METHODS
  Perineal body length was measured in primigravid women aged 18 to 45 years who were admitted in labor. Women were classified into 1 of 6 racial groups: White, Filipino, Japanese, Chinese, Native Hawaiian, or Micronesian. The primary outcome, perineal body length, was compared using analysis of variance.
  
  
  RESULTS
  A total of 200 women were recruited. There were no significant differences in perineal body length (P = 0.42) and severe perineal lacerations (P = 0.82) between the different racial groups. The mean (SD) perineal body length of women who had a severe laceration was 3.9 (0.5) versus 3.9 (0.6) cm in women who did not have a severe laceration (P= 0.98).
  
  
  CONCLUSIONS
  Perineal body length does not seem to differ among the different racial groups studied and therefore an unlikely cause of racial variation in rates of severe perineal lacerations.
authors.affiliation: Department of Obstetrics, Gynecology, and Women's Health, John A. Burns School of Medicine, University of Hawaii, 1319 Punahou St, Suite 824, Honolulu, HI 96826, USA. paijong@hawaii.edu
authors.forename: Pai-Jong Stacy
authors.initials: PJ
authors.lastname: Tsai
authors.forename: Ian A
authors.initials: IA
authors.lastname: Oyama
authors.forename: Mark
authors.initials: M
authors.lastname: Hiraoka
authors.forename: Steven
authors.initials: S
authors.lastname: Minaglia
authors.forename: Jennifer
authors.initials: J
authors.lastname: Thomas
authors.forename: Bliss
authors.initials: B
authors.lastname: Kaneshiro
mesh_terms: D000328:Adult; D036861:Delivery, Obstetric; D004841:Episiotomy / Q000706:statistics & numerical data; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007747:Labor Stage, First; D010502:Perineum / Q000033:anatomy & histology* / Q000293:injuries*; D011247:Pregnancy; D011446:Prospective Studies; D044469:Racial Groups