title: Reliability of two-dimensional transvaginal sonographic measurement of lower uterine segment thickness using video sequences.
abstract: OBJECTIVE
  To report the intra- and interobserver reliability of measurement of the lower uterine segment (LUS) thickness using transvaginal sonographic videos.
  
  
  METHODS
  A prospective study of 60 women with previous, low-transverse cesarean undergoing LUS examination (36 to 39 weeks) was performed. Two observers independently measured full LUS thickness using transvaginal sonography. A video of the LUS was recorded and analyzed more than 2 months later by both observers. Intra- and interobserver reliability was assessed with median absolute differences and interquartile range (IQR), nonparametric limits of agreement, intraclass correlation coefficients (ICC) with 95% confidence interval (95% CI), and kappa coefficients.
  
  
  RESULTS
  Median full LUS thickness was 3.6 mm (range: 0.9 to 8.0 mm). Intraobserver repeatability was excellent (median difference: 0.2 mm, IQR: 0.1 to 0.4; ICC: 0.94, 95% CI: 0.90 to 0.96; kappa: 1.00). Interobserver (median difference: 0.3 mm, IQR: 0.2 to 1.3; ICC: 0.91, 95% CI: 0.86 to 0.95; kappa: 0.76, 95% CI: 0.54 to 0.98) and intermethod reproducibility (median difference: 0.4 mm, IQR: 0.2 to 0.8; ICC: 0.82, 95% CI: 0.72 to 0.89; kappa: 0.69, 95% CI: 0.43 to 0.94) were good. However, both interobserver and intermethod reproducibility were improved when LUS thickness was below 3 mm.
  
  
  CONCLUSIONS
  Full LUS thickness measured from transvaginal sonographic videos has excellent intra- and interobserver reproducibility and good reproducibility with live transvaginal ultrasound.
authors.affiliation: Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec, Canada.
authors.forename: Amélie
authors.initials: A
authors.lastname: Boutin
authors.forename: Nicole
authors.initials: N
authors.lastname: Jastrow
authors.forename: Mario
authors.initials: M
authors.lastname: Girard
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Roberge
authors.forename: Nils
authors.initials: N
authors.lastname: Chaillet
authors.forename: Normand
authors.initials: N
authors.lastname: Brassard
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bujold
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015588:Observer Variation; D009929:Organ Size; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal / Q000379:methods* / Q000706:statistics & numerical data; D014597:Uterine Rupture; D014599:Uterus / Q000000981:diagnostic imaging*; D016064:Vaginal Birth after Cesarean