title: The relationship of placenta previa and history of induced abortion.
abstract: OBJECTIVE
  We evaluated the risk of placenta previa being associated with a history of induced abortion by different surgical procedures.
  
  
  METHODS
  Cases (n=192) were women who had a singleton delivery complicated by placenta previa at a major obstetric care hospital in western Washington state between April 1, 1990 and December 31, 1992. Controls (n=622) were women with singleton deliveries not complicated by placenta previa or abruption. Odds ratios, determined by logistic regression, approximate the relative risks.
  
  
  RESULTS
  Vacuum aspiration abortion was not associated with an increased risk of placenta previa (OR 0.9, 95% CI 0.6-1.5). However, the risk of placenta previa increased with the number of sharp curettage abortions (OR 2.9, 95% CI 1.0-8.5 for > or =3).
  
  
  CONCLUSIONS
  Risk of placenta previa may be increased in a dose response fashion by multiple sharp curettage abortions. However, vacuum aspiration does not confer an increased risk, and may be a better alternative.
authors.affiliation: Fred Hutchinson Cancer Research Center, Division of Public Health Sciences, Seattle, WA, USA. lgodefro@fhcrc.org
authors.forename: L G
authors.initials: LG
authors.lastname: Johnson
authors.forename: B A
authors.initials: BA
authors.lastname: Mueller
authors.forename: J R
authors.initials: JR
authors.lastname: Daling
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects* / Q000379:methods*; D000328:Adult; D016022:Case-Control Studies; D004107:Dilatation and Curettage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D010298:Parity; D010923:Placenta Previa / Q000209:etiology*; D011247:Pregnancy; D012307:Risk Factors; D014619:Vacuum Curettage