title: Following declining human chorionic gonadotropin values in pregnancies of unknown location: when is it safe to stop?
abstract: OBJECTIVE
  To determine if the pattern of decline in hCG curves can discriminate spontaneous abortion (SAB) from ectopic pregnancy (EP).
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  University hospitals.
  
  
  METHODS
  A total of 1,551 women with symptomatic pregnancy of unknown location (PUL) and decreasing hCG values.
  
  
  METHODS
  None.
  
  
  METHODS
  Percentage change in hCG; days and visits to final diagnosis.
  
  
  RESULTS
  Of the 1,551 women with a PUL and declining hCG, 146 were ultimately diagnosed with EP and 1,405 with SAB. An 85% hCG drop within 4 days or a 95% hCG drop within 7 days both ruled out an EP 100% of the time. Applying the 4-day cutoff to this population would have saved 16% of the SAB population (229/1,405) a total of 2,841 person-days and 277 clinical visits. Applying the 7-day cutoff would have saved 9% of the SAB population (126/1,405) a total of 1,294 person-days and 182 clinical visits. These cutoffs were separately validated on a group of 179 EPs collected from three university clinical centers. In that population, each cutoff separately ruled out EP 100% of the time.
  
  
  CONCLUSIONS
  The decline in serum hCG is slower in EPs than in SAB and can be used to aid clinicians in the frequency and duration of follow-up. Costs and patient time may be saved by allowing women who meet one of these criteria to be followed less frequently.
authors.affiliation: Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: katherine.cameron@uphs.upenn.edu.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Cameron
authors.affiliation: Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Suneeta
authors.initials: S
authors.lastname: Senapati
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mary D
authors.initials: MD
authors.lastname: Sammel
authors.affiliation: Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, California.
authors.forename: Karine
authors.initials: K
authors.lastname: Chung
authors.affiliation: Department of Obstetrics and Gynecology, University of Miami School of Medicine, Miami, Florida.
authors.forename: Peter
authors.initials: P
authors.lastname: Takacs
authors.affiliation: Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Obstetrics and Gynecology, Rutgers-Robert Wood Johnson and Reproductive Medicine Associates of New Jersey, New Brunswick, New Jersey.
authors.forename: Thomas
authors.initials: T
authors.lastname: Molinaro
authors.affiliation: Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Kurt T
authors.initials: KT
authors.lastname: Barnhart
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood* / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D002648:Child; D006063:Chorionic Gonadotropin / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University / Q000639:trends*; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000097:blood* / Q000175:diagnosis*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006063:Chorionic Gonadotropin
keywords: ectopic pregnancy; hCG curves; pregnancy of unknown location