title: Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding: meta-analysis of cohort studies.
abstract: OBJECTIVE
  To determine the accuracy with which a single progesterone measurement in early pregnancy discriminates between viable and non-viable pregnancy.
  
  
  METHODS
  Systematic review and meta-analysis of diagnostic accuracy studies.
  
  
  METHODS
  Medline, Embase, CINAHL, Web of Science, ProQuest, Conference Proceedings Citation Index, and the Cochrane Library from inception until April 2012, plus reference lists of relevant studies.
  
  
  METHODS
  Studies were selected on the basis of participants (women with spontaneous pregnancy of less than 14 weeks of gestation); test (single serum progesterone measurement); outcome (viable intrauterine pregnancy, miscarriage, or ectopic pregnancy) diagnosed on the basis of combinations of pregnancy test, ultrasound scan, laparoscopy, and histological examination; design (cohort studies of test accuracy); and sufficient data being reported.
  
  
  RESULTS
  26 cohort studies, including 9436 pregnant women, were included, consisting of 7 studies in women with symptoms and inconclusive ultrasound assessment and 19 studies in women with symptoms alone. Among women with symptoms and inconclusive ultrasound assessments, the progesterone test (5 studies with 1998 participants and cut-off values from 3.2 to 6 ng/mL) predicted a non-viable pregnancy with pooled sensitivity of 74.6% (95% confidence interval 50.6% to 89.4%), specificity of 98.4% (90.9% to 99.7%), positive likelihood ratio of 45 (7.1 to 289), and negative likelihood ratio of 0.26 (0.12 to 0.57). The median prevalence of a non-viable pregnancy was 73.2%, and the probability of a non-viable pregnancy was raised to 99.2% if the progesterone was low. For women with symptoms alone, the progesterone test had a higher specificity when a threshold of 10 ng/mL was used (9 studies with 4689 participants) and predicted a non-viable pregnancy with pooled sensitivity of 66.5% (53.6% to 77.4%), specificity of 96.3% (91.1% to 98.5%), positive likelihood ratio of 18 (7.2 to 45), and negative likelihood ratio of 0.35 (0.24 to 0.50). The probability of a non-viable pregnancy was raised from 62.9% to 96.8%.
  
  
  CONCLUSIONS
  A single progesterone measurement for women in early pregnancy presenting with bleeding or pain and inconclusive ultrasound assessments can rule out a viable pregnancy.
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre University of Amsterdam, Amsterdam, Netherlands.
authors.forename: Jorine
authors.initials: J
authors.lastname: Verhaegen
authors.forename: Ioannis D
authors.initials: ID
authors.lastname: Gallos
authors.forename: Norah M
authors.initials: NM
authors.lastname: van Mello
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdel-Aziz
authors.forename: Yemisi
authors.initials: Y
authors.lastname: Takwoingi
authors.forename: Hoda
authors.initials: H
authors.lastname: Harb
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Deeks
authors.forename: Ben W J
authors.initials: BW
authors.lastname: Mol
authors.forename: Arri
authors.initials: A
authors.lastname: Coomarasamy
mesh_terms: D015746:Abdominal Pain / Q000209:etiology*; D000022:Abortion, Spontaneous / Q000097:blood / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011374:Progesterone / Q000097:blood*; D012680:Sensitivity and Specificity; D014592:Uterine Hemorrhage / Q000209:etiology*
chemical_list: D015415:Biomarkers; D011374:Progesterone