title: Endoanal ultrasound for detection of sphincter defects following childbirth.
abstract: OBJECTIVE
  The objectives of this study were to estimate the rates of sonographically detected anal sphincter defects within 72 h of childbirth and to evaluate intra- and interobserver agreement using three-dimensional (3-D) endoanal sonography data.
  
  
  METHODS
  This is a prospective observational study of primiparous women delivered vaginally. Women without clinically identified anal sphincter lacerations underwent endoanal ultrasonography within 72 h of delivery. Intra- and interobserver agreement for diagnosis of sphincter defects using 3-D endoanal sonography data was calculated using kappa statistics.
  
  
  RESULTS
  The rate of sphincter defects in 107 women undergoing 3-D endoanal sonography was 12 %. Characteristics of women with sonographically detected sphincter defects, compared to those without, included a significantly increased rate of clinically diagnosed second-degree lacerations (54 vs 20 %, p 0.008). The intra- and interobserver agreement for diagnosis of sphincter defects using 3-D endoanal sonography data was 0.82 [confidence interval (CI) 0.66-0.99] and 0.72 (CI 0.54-0.92), respectively.
  
  
  CONCLUSIONS
  Anal sphincter defects detected using endoanal sonography are common, occurring in 12 % of primiparous women, and are significantly associated with other less severe perineal lacerations. Overall and combining sonographically detected defects with clinically diagnosed lacerations, we estimate that 17.8 % of primiparous women delivered vaginally sustain anal sphincter injuries. The intraobserver agreement for diagnosis of sphincter defects is very good and the interobserver agreement is good.
authors.affiliation: Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9032, USA. marlene.corton@utsouthwestern.edu
authors.forename: Marlene M
authors.initials: MM
authors.lastname: Corton
authors.forename: Donald D
authors.initials: DD
authors.lastname: McIntire
authors.forename: Diane M
authors.initials: DM
authors.lastname: Twickler
authors.forename: Shanna
authors.initials: S
authors.lastname: Atnip
authors.forename: Joseph I
authors.initials: JI
authors.lastname: Schaffer
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
mesh_terms: D000293:Adolescent; D000328:Adult; D001003:Anal Canal / Q000000981:diagnostic imaging* / Q000293:injuries*; D019160:Endosonography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D015588:Observer Variation; D007744:Obstetric Labor Complications / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D017695:Soft Tissue Injuries / Q000000981:diagnostic imaging* / Q000453:epidemiology; D013781:Texas / Q000453:epidemiology; D055815:Young Adult