title: Threatened abortion: A risk factor for poor pregnancy outcome, a population-based screening study.
abstract: OBJECTIVE
  The purpose of this study was to determine whether patients with first-trimester threatened abortion are at increased risk for poor pregnancy outcome.
  
  
  METHODS
  A large prospective multicenter database was studied. Subjects were divided into three groups: (1) no bleeding, (2) light bleeding, and (3) heavy bleeding. Univariate and multivariable logistic regression analyses were used.
  
  
  RESULTS
  The study comprised 16,506 patients: 14,160 patients without bleeding, 2094 patients with light bleeding, and 252 patients with heavy bleeding. Patients with vaginal bleeding, light or heavy, were more likely to experience a spontaneous loss before 24 weeks of gestation (odds ratio, 2.5 and 4.2, respectively) and cesarean delivery (odds ratio, 1.1 and 1.4, respectively). Light bleeding subjects were more likely to have preeclampsia (odds ratio, 1.5), preterm delivery (odds ratio, 1.3), and placental abruption (odds ratio, 1.6). Heavy vaginal bleeding subjects were more likely to have intrauterine growth restriction (odds ratio, 2.6), preterm delivery (odds ratio, 3.0), preterm premature rupture of membranes (odds ratio, 3.2), and placental abruption (odds ratio, 3.6).
  
  
  CONCLUSIONS
  First-trimester vaginal bleeding is an independent risk factor for adverse obstetric outcome that is directly proportional to the amount of bleeding.
authors.affiliation: Columbia Presbyterian Medical Center, New York, NY, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Weiss
authors.forename: Fergal D
authors.initials: FD
authors.lastname: Malone
authors.forename: John
authors.initials: J
authors.lastname: Vidaver
authors.forename: Robert H
authors.initials: RH
authors.lastname: Ball
authors.forename: David A
authors.initials: DA
authors.lastname: Nyberg
authors.forename: Christine H
authors.initials: CH
authors.lastname: Comstock
authors.forename: Gary D
authors.initials: GD
authors.lastname: Hankins
authors.forename: Richard L
authors.initials: RL
authors.lastname: Berkowitz
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Gross
authors.forename: Lorraine
authors.initials: L
authors.lastname: Dugoff
authors.forename: Ilan E
authors.initials: IE
authors.lastname: Timor-Tritsch
authors.forename: Mary E
authors.initials: ME
authors.lastname: D'Alton
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000209:etiology; D000033:Abortion, Threatened / Q000150:complications / Q000503:physiopathology*; D000037:Abruptio Placentae / Q000209:etiology; D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data; D005260:Female; D005317:Fetal Growth Retardation / Q000209:etiology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D007752:Obstetric Labor, Premature / Q000209:etiology; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000150:complications; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D012307:Risk Factors; D012720:Severity of Illness Index; D014592:Uterine Hemorrhage / Q000150:complications / Q000503:physiopathology