title: Risk factors for ectopic pregnancy in women with symptomatic first-trimester pregnancies.
abstract: OBJECTIVE
  To evaluate the association between ectopic pregnancy (EP) and clinical and historical factors among women presenting with pain and/or bleeding in early pregnancy.
  
  
  METHODS
  Nested case-control study.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  Women with symptomatic early pregnancies of unknown location presenting for care between January 1, 1990 and July 31, 1999.
  
  
  METHODS
  None.
  
  
  METHODS
  Clinical and historical risk factors were compared between women with EP and women with ongoing intrauterine pregnancies or spontaneous abortions.
  
  
  RESULTS
  The following factors were associated with increased risk of EP: prior EP (odds ratio, 2.98 [95% confidence interval, 1.88-4.73] for one prior EP and 16.04 [5.39-47.72] for 2 or more), pelvic inflammatory disease history (1.5 [1.11-2.05]), pain at presentation (1.42 [1.06-1.92]), vaginal bleeding at presentation (1.42 [1.04-1.93]), and hCG of 501-2,000 mIU/mL (1.73 [1.24-2.42]). Age younger than 25 years (0.59 [0.41-0.85]) and a history of abortion were protective from EP (0.58 [0.38-0.90]). Prior nontubal pelvic surgery, past intrauterine device use, prior cesarean section, and current cervical infection demonstrated no association with EP.
  
  
  CONCLUSIONS
  Evaluation of women with a symptomatic early pregnancy confirms and refutes some of the classical risk factors for EP. Prior EP is a strong risk factor, whereas pelvic inflammatory disease has an unexpected weak association. Previous abortion was found to have a negative association, whereas nontubal surgery, cesarean section, and a history of or concomitant cervical infection have no association. Knowledge of historical and clinical factors associated with EP may aid in early diagnosis.
authors.affiliation: Penn Fertility Care, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, USA. kbarnhart@mail.obgyn.upenn.edu
authors.forename: Kurt T
authors.initials: KT
authors.lastname: Barnhart
authors.forename: Mary D
authors.initials: MD
authors.lastname: Sammel
authors.forename: Clarisa R
authors.initials: CR
authors.lastname: Gracia
authors.forename: Jesse
authors.initials: J
authors.lastname: Chittams
authors.forename: Amy C
authors.initials: AC
authors.lastname: Hummel
authors.forename: Alka
authors.initials: A
authors.lastname: Shaunik
mesh_terms: D000328:Adult; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D010414:Pennsylvania / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011261:Pregnancy Trimester, First; D011271:Pregnancy, Ectopic / Q000453:epidemiology*; D016016:Proportional Hazards Models; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors