title: How well can pelvic floor muscles with major defects contract? A cross-sectional comparative study 6 weeks after delivery using transperineal 3D/4D ultrasound and manometer.
abstract: OBJECTIVE
  To investigate ability to contract, vaginal resting pressure (VRP), pelvic floor muscle (PFM) strength and PFM endurance 6 weeks after vaginal delivery in primiparous women, with and without major defects of the levator ani (LA) muscle.
  
  
  METHODS
  Cross-sectional comparative study.
  
  
  METHODS
  Akershus University Hospital, Norway.
  
  
  METHODS
  A cohort of 175 singleton primiparous women delivering vaginally after more than 32 weeks of gestation.
  
  
  METHODS
  Major LA defects were assessed by 3D/4D transperineal ultrasound at maximal PFM contraction, using tomographic imaging. VRP, PFM strength and PFM endurance were measured vaginally by manometer. Data were analysed by independent-samples Student's t test, chi-square test, and standard multiple and simple linear regression.
  
  
  METHODS
  VRP, PFM strength and PFM endurance.
  
  
  RESULTS
  Of the women included in the study, 4% were not able to contract their PFM 6 weeks after delivery. Women with major LA defects (n = 55) had 47% lower PFM strength and 47% lower endurance when compared with women without major LA defects (n = 120). Mean differences were 7.5 cmH2O (95% CI 5.1-9.9, P < 0.001) and 51.2 cmH2O seconds (95% CI 32.8-69.6, P < 0.001), respectively. These estimates were unchanged by adjustment in multivariable linear regression for potentially confounding demographic and obstetric factors. No difference was found regarding VRP (P = 0.670).
  
  
  CONCLUSIONS
  Women with major LA defects after vaginal delivery had pronounced lower PFM strength and endurance than women without such defects; however, most women with major LA defects were able to contract the PFM. This indicates a potential capacity by non-injured muscle fibres to compensate for loss in muscle strength, even at an early stage after delivery.
authors.affiliation: Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway; Department of Obstetrics and Gynaecology, Akershus University Hospital, Lørenskog, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Hilde
authors.forename: J
authors.initials: J
authors.lastname: Staer-Jensen
authors.forename: F
authors.initials: F
authors.lastname: Siafarikas
authors.forename: K
authors.initials: K
authors.lastname: Gjestland
authors.forename: M
authors.initials: M
authors.lastname: Ellström Engh
authors.forename: K
authors.initials: K
authors.lastname: Bø
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008365:Manometry; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D036801:Parturition / Q000502:physiology; D017773:Pelvic Floor / Q000000981:diagnostic imaging* / Q000502:physiology*; D049590:Postpartum Period / Q000502:physiology*; D014463:Ultrasonography
keywords: Levator ani defects; muscle endurance; muscle strength; pelvic floor muscles; vaginal delivery; vaginal resting pressure