title: Can risk factors, clinical history and symptoms be used to predict risk of ectopic pregnancy in women attending an early pregnancy assessment unit?
abstract: OBJECTIVE
  To examine whether risk factors and symptoms may be used to predict the likelihood of ectopic pregnancy (EP) in women attending early pregnancy assessment units in the UK.
  
  
  METHODS
  This was an observational cohort study of pregnant women under 12 weeks' gestation who were recruited from three London university hospitals between August 2012 and April 2013. One hospital continued recruitment between January and June 2015. A standardized information sheet incorporating patient demographics, medical history and symptoms was completed by patients and confirmed by examining clinicians. The outcome measure was final pregnancy location.
  
  
  RESULTS
  There were 1320 eligible patients included in the analysis, with a total of 72 EPs (rate of 6%). Pelvic pain and diarrhea > three times in the previous 24 h were independent symptoms that increased the risk of EP, with relative risks of 2.4 (95% CI, 1.4-4.0; P = 0.002) and 2.2 (95% CI, 1.08-4.5; P = 0.03), respectively. The only other independent marker of risk of EP was duration of vaginal bleeding; the risk of EP increased by 20% (95% CI, 14%-27%) for every 1-day increment in duration (P < 0.001). A logistic regression model incorporating these factors demonstrated an area under the receiver-operating characteristics curve of 0.73 (95% CI, 0.67-0.79). The prevalence of EP was low when there was no pelvic pain, no diarrhea and the duration of bleeding was ≤ 3 days, with an EP rate of 2% (6/391). In the presence of a single risk factor, the EP rate increased to 5% (29/631) when only pelvic pain was present, 8% (1/12) when only diarrhea > three times in the previous 24 h was reported and 9% (9/103) when there was only vaginal bleeding with a duration > 3 days. Women with pelvic pain and vaginal bleeding of any severity for > 3 days had a high EP rate of 16% (23/146). In the nine women who also reported diarrhea > three times in the previous 24 h, two had EP.
  
  
  CONCLUSIONS
  Only the presence of pelvic pain, diarrhea > three times in the previous 24 h and duration of bleeding were symptoms that significantly increased the risk for EP in women attending early pregnancy assessment units. Risk factors and symptoms alone could not be used to predict reliably an EP. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: F
authors.initials: F
authors.lastname: Ayim
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Tapp
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Guha
authors.affiliation: Department of Development and Regeneration, Campus Gasthuisberg, KU Leuven, Leuven, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Ameye
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Al-Memar
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sayasneh
authors.affiliation: Chelsea and Westminster Hospital, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Bottomley
authors.affiliation: St Mary's Hospital, Imperial College, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Gould
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Stalder
authors.affiliation: Department of Development and Regeneration, Campus Gasthuisberg, KU Leuven, Leuven, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Timmerman
authors.affiliation: Tommy's National Centre for Miscarriage Research, Queen Charlotte's and Chelsea Hospital, Imperial College, London, UK.|Department of Development and Regeneration, Campus Gasthuisberg, KU Leuven, Leuven, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Bourne
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D017699:Pelvic Pain / Q000150:complications*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011271:Pregnancy, Ectopic / Q000175:diagnosis* / Q000209:etiology; D012307:Risk Factors; D006113:United Kingdom; D014592:Uterine Hemorrhage / Q000150:complications*; D055815:Young Adult
keywords: diagnosis; ectopic pregnancy; fallopian tube; miscarriage; tubal pregnancy; ultrasonography