title: Planned vaginal delivery versus planned cesarean delivery in cases of low-lying placenta.
abstract: OBJECTIVE
  To assess the applicability of trial of labor in cases of low-lying placenta.
  
  
  METHODS
  In this observational cohort study, we collected data from the women with low-lying placenta delivered at our hospital between April 2012 and December 2015. Low-lying placenta was diagnosed when the length from the placental lowest edge to the internal cervical os (placenta-os distance) was 0-20 mm at 36 gestational weeks. Planned mode of delivery for each case was determined by patient's preference. Maternal and neonatal outcomes were compared between the planned vaginal delivery group (N = 11) and the planned cesarean delivery group (N = 7).
  
  
  RESULTS
  All the women in the planned cesarean delivery group underwent scheduled cesarean section at 37-38 gestational weeks. Three cases in the planned vaginal delivery group required emergency cesarean section for uncontrollable antepartum bleeding. The intrapartum blood loss was significantly smaller in the planned vaginal delivery group than in the planned cesarean delivery group (946 ± 204 g vs. 1649 ± 256 g, p = 0.047). Umbilical arterial blood pH was similar between the two groups. All the women requiring emergency cesarean section were accompanied by marginal sinus.
  
  
  CONCLUSIONS
  Trial of labor can be offered to all the women with low-lying placenta except for those accompanied by marginal sinus.
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Taga
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Yukiyasu
authors.initials: Y
authors.lastname: Sato
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Chieko
authors.initials: C
authors.lastname: Sakae
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Satake
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Emoto
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Maruyama
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Mise
authors.affiliation: a Department of Obstetrics and Gynecology , Otsu Red Cross Hospital , Otsu , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kim
mesh_terms: D000328:Adult; D015331:Cohort Studies; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007744:Obstetric Labor Complications; D010923:Placenta Previa / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D014219:Trial of Labor; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries; D014592:Uterine Hemorrhage / Q000209:etiology*; D055815:Young Adult
keywords: Antepartum bleeding; marginal sinus; placenta previa; placental migration; transvaginal ultrasonography