title: Placenta previa: distance to internal os and mode of delivery.
abstract: OBJECTIVE
  The purpose of this study was to relate the mode of delivery and outcomes in a cohort of cases of placenta previa that had the last transvaginal ultrasonographic scan <28 days before delivery.
  
  
  METHODS
  Cases in which the placental edge overlapped the internal cervical (n = 42) underwent cesarean section delivery. Labor was allowed in those with placental edge to internal os distance of 1-10 mm (group 1, 24 women) and those with a distance of 11-20 mm (group 2, 29 women).
  
  
  RESULTS
  Rates of cesarean section delivery (75% vs 31%; odds ratio, 6.7; 95% confidence interval [CI], 2-22) and of bleeding before labor (29% vs 3%; odds ratio, 11.5; 95% CI, 1.6-76.7) were higher in group 1 than in group 2. Blood loss at delivery (662 +/- 466 mL vs 510 +/- 547 mL) and rate of severe postpartum hemorrhage (21% vs 10%; odds ratio, 2.3; 95% CI, 0.5-9.7) were similar in the 2 groups.
  
  
  CONCLUSIONS
  More than two-thirds of women with a placental edge to cervical os distance of >10 mm deliver vaginally without increased risk of hemorrhage.
authors.affiliation: Department of Obstetrics and Gynecology, University of Milano-Bicocca, Monza, Italy. pvergani@yahoo.it
authors.forename: Patrizia
authors.initials: P
authors.lastname: Vergani
authors.forename: Sara
authors.initials: S
authors.lastname: Ornaghi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Pozzi
authors.forename: Pietro
authors.initials: P
authors.lastname: Beretta
authors.forename: Francesca Maria
authors.initials: FM
authors.lastname: Russo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Follesa
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ghidini
mesh_terms: D000328:Adult; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D010923:Placenta Previa / Q000000981:diagnostic imaging*; D006473:Postpartum Hemorrhage / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal