title: Impact of childbirth and mode of delivery on vaginal resting pressure and on pelvic floor muscle strength and endurance.
abstract: OBJECTIVE
  We sought to study impact of delivery mode on vaginal resting pressure (VRP) and on pelvic floor muscle (PFM) strength and endurance, and whether these measurements differed in women with and without urinary incontinence.
  
  
  METHODS
  We conducted a cohort study following 277 nulliparous women from midpregnancy to 6 weeks postpartum. Manometer was used for PFM measurements; differences were analyzed by t test (within groups) and analysis of variance (between groups).
  
  
  RESULTS
  Only VRP changed significantly (10% reduction, P = .001) after emergency cesarean section. After normal and instrumental vaginal delivery, VRP was reduced by 29% and 30%; PFM strength by 54% and 66%; and endurance by 53% and 65%, respectively. Significant differences for all PFM measures (P < .001) were found when comparing cesarean vs normal and instrumental vaginal delivery, respectively. Urinary continent women at both time points had significantly higher PFM strength and endurance than incontinent counterparts (P < .05).
  
  
  CONCLUSIONS
  Pronounced reductions in VRP and in PFM strength and endurance were found after vaginal delivery. Continent women were stronger than incontinent counterparts.
authors.affiliation: Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway.
authors.forename: Gunvor
authors.initials: G
authors.lastname: Hilde
authors.forename: Jette
authors.initials: J
authors.lastname: Stær-Jensen
authors.forename: Franziska
authors.initials: F
authors.lastname: Siafarikas
authors.forename: Marie Ellström
authors.initials: ME
authors.lastname: Engh
authors.forename: Ingeborg Hoff
authors.initials: IH
authors.lastname: Brækken
authors.forename: Kari
authors.initials: K
authors.lastname: Bø
mesh_terms: D000009:Abdominal Muscles / Q000502:physiology; D000328:Adult; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D036801:Parturition / Q000502:physiology*; D017773:Pelvic Floor / Q000502:physiology*; D049590:Postpartum Period; D011446:Prospective Studies; D014549:Urinary Incontinence / Q000503:physiopathology; D014621:Vagina / Q000502:physiology