title: Single serum activin a testing to predict ectopic pregnancy.
abstract: BACKGROUND
  Ectopic pregnancy (EP) is an important cause of maternal deaths in early pregnancy because most fatal cases result from delayed diagnosis and inappropriate investigation.
  
  
  OBJECTIVE
  We evaluated whether the measurement of activin A may be useful in the diagnosis of EP in women with unknown pregnancy location.
  
  
  METHODS
  The study was designed as an open observational study.
  
  
  METHODS
  The study was set in a tertiary referral center for obstetric care.
  
  
  METHODS
  Patients were women with unknown pregnancy location (n = 536) who had complaints of bleeding, pain, or cramping.
  
  
  METHODS
  Interventions included clinical examination; transvaginal ultrasound scan; human chorionic gonadotropin (hCG), progesterone, and activin A measurements; laparoscopy; uterine curettage; and histological examination.
  
  
  METHODS
  Main outcome measures were pregnancy outcomes and evaluation of sensitivity, specificity, and predictive values of hCG, progesterone, and activin A as diagnostic tests for the detection of EP.
  
  
  RESULTS
  Pregnancy outcomes included 155 (28.9%) viable intrauterine pregnancies (IUP), 305 (56.9%) first-trimester spontaneous abortion (SAB), and 76 (14.2%) EP. SAB had the lowest (P < 0.0001) hCG and progesterone concentrations, significantly lower than EP (P < 0.001) and IUP (P < 0.001). In EP, levels were significantly (P < 0.001) lower than in IUP. On the contrary, activin A levels were lowest (P < 0.0001) in EP, significantly lower than in SAB (P < 0.001) and IUP (P < 0.001). IUP had significantly (P < 0.001) lower activin A levels than SAB. When evaluated by the receiver operating curve analysis, activin A at the cutoff of 0.37 ng/ml combined a sensitivity and a specificity of 100 and 99.6%, respectively, for prediction of EP. When activin A concentrations were below the cutoff, the positive predictive value for EP was 97.43%, and 0% for concentrations higher than 0.37 ng/ml.
  
  
  CONCLUSIONS
  Activin A measurement may identify patients at risk of EP with a high sensibility and specificity.
authors.affiliation: Chair of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Policlinico Le Scotte, viale Bracci, 53100 Siena, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Florio
authors.forename: Filiberto Maria
authors.initials: FM
authors.lastname: Severi
authors.forename: Caterina
authors.initials: C
authors.lastname: Bocchi
authors.forename: Stefano
authors.initials: S
authors.lastname: Luisi
authors.forename: Massimo
authors.initials: M
authors.lastname: Mazzini
authors.forename: Secondo
authors.initials: S
authors.lastname: Danero
authors.forename: Michela
authors.initials: M
authors.lastname: Torricelli
authors.forename: Felice
authors.initials: F
authors.lastname: Petraglia
mesh_terms: D028341:Activins / Q000097:blood*; D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011271:Pregnancy, Ectopic / Q000097:blood* / Q000175:diagnosis*; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D012372:ROC Curve
chemical_list: D006063:Chorionic Gonadotropin; C422405:activin A; D028341:Activins; D011374:Progesterone