title: Determination of a cutoff value for pelvic floor distensibility using the Epi-no balloon to predict perineal integrity in vaginal delivery: ROC curve analysis. Prospective observational single cohort study.
abstract: OBJECTIVE
  Several risk factors are involved in perineal lacerations during vaginal delivery. However, little is known about the influence of perineal distensibility as a protective factor. The aim here was to determine a cutoff value for pelvic floor distensibility measured using the Epi-no balloon, which could be used as a predictive factor for perineal integrity in vaginal delivery.
  
  
  METHODS
  Prospective observational single cohort study conducted in a maternity hospital.
  
  
  METHODS
  A convenience sample of 227 consecutive at-term parturients was used. All women had a single fetus in the vertex presentation, with up to 9.0 cm of dilation. The maximum dilation of the Epi-no balloon was measured using a tape measure after it had been inflated inside the vagina up to the parturients' maximum tolerance. The receiver operating characteristic (ROC) curve was used to obtain the Epi-no circumference measurement with best sensitivity and specificity.
  
  
  RESULTS
  Among the 161 patients who were included in the study, 50.9% underwent episiotomy, 21.8% presented lacerations and 27.3% retained an intact perineum. Age > 25.9 years; number of pregnancies > 3.4; number of deliveries > 2.2 and circumference measured by Epi-no > 21.4 cm were all directly correlated with an intact perineum. Circumference measurements using the Epi-no balloon that were greater than 20.8 cm showed sensitivity and specificity of 70.5% and 66.7% (area under curve = 0.713), respectively, as a predictive factor for an intact perineum in vaginal delivery.
  
  
  CONCLUSIONS
  Circumferences greater than 20.8 cm achieved using the Epi-no balloon are a predictive factor for perineal integrity in parturients.
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Miriam Raquel Diniz
authors: MR
authors: Zanetti
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Carla Dellabarba
authors: CD
authors: Petricelli
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Sandra Maria
authors: SM
authors: Alexandre
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Aline
authors: A
authors: Paschoal
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Edward
authors: E
authors: Araujo Júnior
authors: Department of Obstetrics, Universidade Federal de São Paulo, São Paulo, Brazil.
authors: Mary Uchiyama
authors: MU
authors: Nakamura
mesh_terms: D000328:Adult; D036861:Delivery, Obstetric; D004841:Episiotomy; D005260:Female; D020073:Gravidity; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D007744:Obstetric Labor Complications; D017773:Pelvic Floor / Q000502:physiology*; D010502:Perineum / Q000293:injuries* / Q000294:innervation; D011247:Pregnancy; D011446:Prospective Studies; D012372:ROC Curve