title: Size of the urogenital hiatus in the levator ani muscles in normal women and women with pelvic organ prolapse.
abstract: OBJECTIVE
  Compare urogenital hiatus size in normal women and women with pelvic organ prolapse.
  
  
  METHODS
  The sagittal and transverse urogenital hiatus diameters were measured and hiatus area calculated in 300 women whose support was scored using a modified Baden system.
  
  
  RESULTS
  In women with normal support and without prior surgery, hiatus area was 5.4 cm2 (+/-1.71 standard deviation [SD], n = 197). In women with uncorrected clinical prolapse (grade 2-3), the area of the hiatus was enlarged (9.6 cm2 +/- 3.97, n = 34, P < .05) and became larger with progressive prolapse (grade 0, 5.4 cm2 +/- 1.71, n = 197; grade 1, 7.3 cm2 +/- 1.91, n = 27; grade 2, 8.3 cm2 +/- 2.45, n = 18; grade 3, 11.0 cm2 +/- 4.90, n = 16). When matched for age and parity, prolapse patients had a larger hiatus than normal women. Women with recurrent prolapse had a larger hiatus than cured women (13.3 cm2 +/- 3.86, n = 8 compared with 8.1 cm2 +/- 2.44, n = 16, P < .05) or women with recurrence after one operation (8.9 cm2 +/- 1.77, n = 18, P < .05). Hiatus size in patients surgically cured (8.3 cm2 +/- 2.44, n = 16) did not return to normal (5.4 cm2 +/- 1.71, n = 197, P < .05). Increasing area of the hiatus was correlated with an increase in anterior-posterior diameter (r2 = 0.9, P < .05), was less attributable to increased transverse diameter (r2 = 0.6, P < .05), and was not related to thickness of the perineal body (r2 = 0.0, P > .05).
  
  
  CONCLUSIONS
  Increasing pelvic organ prolapse is associated with increasing urogenital hiatus size; the hiatus is larger after several failed operations than after successful surgery or single failure.
authors.affiliation: Department of Obstetrics and Gynecology, University of Michigan Medical School, Ann Arbor 48109-0216, USA. delancey@umich.edu
authors.forename: J O
authors.initials: JO
authors.lastname: Delancey
authors.forename: W W
authors.initials: WW
authors.lastname: Hurd
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal; D005260:Female; D006801:Humans; D008875:Middle Aged; D009132:Muscles / Q000033:anatomy & histology; D017773:Pelvic Floor / Q000033:anatomy & histology* / Q000473:pathology; D010502:Perineum / Q000033:anatomy & histology* / Q000473:pathology; D011391:Prolapse; D012016:Reference Values