title: Displacement and recovery of the vesical neck position during pregnancy and after childbirth.
abstract: OBJECTIVE
  (i) To describe the displacement and recovery of the vesical neck position during pregnancy and after childbirth and (ii) to discriminate between compliance of the vesical neck supporting structures with and without pelvic floor contraction.
  
  
  METHODS
  We focussed on the biomechanical properties of the vesical neck supporting structures during pregnancy and after childbirth by calculating the compliance and the hysteresis as a result from of abdominal pressure measurements and simultaneous perineal ultrasound.
  
  
  RESULTS
  This study shows that compliance of the supporting structures remains relatively constant during pregnancy and returns to normal values 6 months after childbirth. Hysteresis, however, showed an increase after childbirth, persisting at least until 6 months post partum.
  
  
  CONCLUSIONS
  Vaginal delivery may stretch and or load beyond the physiological properties of the pelvic floor tissue and in this way may lead to irreversible changes in tissue properties which play an important role in the urethral support continence mechanism.
authors.affiliation: Martini Hospital Groningen, Groningen, The Netherlands. jac.wijma@wanadoo.nl
authors.forename: Jacobus
authors.initials: J
authors.lastname: Wijma
authors.forename: Annemarie E
authors.initials: AE
authors.lastname: Weis Potters
authors.forename: Thomas W
authors.initials: TW
authors.lastname: van der Mark
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Tinga
authors.forename: Jan G
authors.initials: JG
authors.lastname: Aarnoudse
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D003187:Compliance; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D036801:Parturition; D017773:Pelvic Floor / Q000000981:diagnostic imaging / Q000502:physiology*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D011446:Prospective Studies; D014463:Ultrasonography; D014521:Urethra / Q000000981:diagnostic imaging / Q000502:physiology*; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000502:physiology*; D014636:Valsalva Maneuver / Q000502:physiology