title: Placenta praevia and the risk of adverse outcomes during second trimester abortion: A retrospective cohort study.
abstract: BACKGROUND
  There are few reports in the literature of the risks associated with second trimester abortion in women with placenta praevia (PP). We hypothesise that PP increases the risk of complications.
  
  
  OBJECTIVE
  We sought to determine if PP is associated with a higher risk of blood loss and blood transfusion at the time of dilation and evacuation (D&E).
  
  
  METHODS
  The records of 612 consecutive women undergoing abortion at 15-24 weeks of gestation were reviewed. Participant characteristics, need for blood transfusion, estimated blood loss (EBL) during the abortion and other complications were compared between women with and without ultrasound-documented PP.
  
  
  RESULTS
  Eighty-seven of 612 (14.2%, 95% CI 11.5-17.2%) women had ultrasound-documented PP. The rate of blood transfusion was 3.4 and 1.3% in the group with PP and without PP, respectively (adjusted relative risk (RR = 2.8, 95% CI 0.7-11.3). An estimated blood loss of 500 cc or greater during the D&E procedure was observed in 12.6% of women in the PP group compared with 4.2% of women in the group without PP (adjusted RR 3.1, 95% CI 1.4-6.8, P = 0.004).
  
  
  CONCLUSIONS
  Second-trimester abortion in women with PP is associated with a higher risk of blood loss of 500 cc or greater. Our study represents a larger sample size of patients with PP undergoing second-trimester abortion than previously reported in the literature. Women with PP may have a higher estimated blood loss and may require access to blood transfusion.
authors.affiliation: Department of Obstetrics and Gynaecology, Sidney Kimmel College of Medicine at Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Perriera
authors.affiliation: Department of Obstetrics and Gynaecology, New York University School of Medicine, New York, New York, USA.
authors.forename: Alan A
authors.initials: AA
authors.lastname: Arslan
authors.affiliation: Department of Obstetrics and Gynaecology, Mount Sinai Beth Israel Medical Center, New York, New York, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Masch
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects*; D000293:Adolescent; D000328:Adult; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D001810:Blood Volume; D005260:Female; D006801:Humans; D010923:Placenta Previa / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012307:Risk Factors; D055815:Young Adult
keywords: abortion; dilation and evacuation; laminaria; placenta praevia; second-trimester abortion