title: Glucose challenge test for detecting gestational diabetes mellitus: a systematic review.
abstract: BACKGROUND
  The best strategy to identify women with gestational diabetes mellitus (GDM) is unclear.
  
  
  OBJECTIVE
  To perform a systematic review to calculate summary estimates of the sensitivity and specificity of the 50-g glucose challenge test for GDM.
  
  
  METHODS
  Systematic search of MEDLINE, EMBASE and Web of Science.
  
  
  METHODS
  Articles that compared the 50-g glucose challenge test with the oral glucose tolerance test (OGTT, with a 75- or 100-g reference standard) before 32 weeks of gestation.
  
  
  METHODS
  Summary estimates of sensitivity and specificity, with 95% confidence intervals and summary receiver operating characteristic curves, were calculated using bivariate random-effects models. Two reviewers independently selected articles that compared the 50 g glucose challenge test to the oral glucose tolerance test (OGTT, 75 or 100 gram, reference standard) before 32 weeks of gestation.
  
  
  RESULTS
  Twenty-six studies were included (13,564 women). Studies that included women with risk factors showed a pooled sensitivity of the 50-g glucose challenge test of 0.74 (95% CI 0.62-0.87), a pooled specificity of 0.77 (95% CI 0.66-0.89) (threshold value of 7.8 mmol/l), a derived positive likelihood ratio (LR) of 3.2 (95% CI 2.0-5.2) and a negative LR of 0.34 (95% CI 0.22-0.53). In studies with consecutive recruitment, the pooled sensitivity was 0.74 (95% CI 0.62-0.87) for a specificity of 0.85 (95% CI 0.80-0.91), with a derived positive LR of 4.9 (95% CI 3.5-7.0) and negative LR of 0.31 (95% CI 0.20-0.47). Increasing the threshold for disease (OGTT result) increased the sensitivity of the challenge test, and decreased the specificity.
  
  
  CONCLUSIONS
  The 50-g glucose challenge test is acceptable to screen for GDM, but cannot replace the OGTT. Further possibilities of combining the 50-g glucose challenge test with other screening strategies should be explored.
authors.affiliation: Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, the Netherlands. marsha.vanleeuwen@amc.uva.nl
authors.forename: M
authors.initials: M
authors.lastname: van Leeuwen
authors.forename: M D
authors.initials: MD
authors.lastname: Louwerse
authors.forename: B C
authors.initials: BC
authors.lastname: Opmeer
authors.forename: J
authors.initials: J
authors.lastname: Limpens
authors.forename: M J
authors.initials: MJ
authors.lastname: Serlie
authors.forename: J B
authors.initials: JB
authors.lastname: Reitsma
authors.forename: B W J
authors.initials: BW
authors.lastname: Mol
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D016640:Diabetes, Gestational / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D019317:Evidence-Based Medicine; D005260:Female; D014943:Global Health; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D015994:Incidence; D008403:Mass Screening / Q000592:standards; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D016032:Randomized Controlled Trials as Topic; D012015:Reference Standards; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose