Lab

Glucose Challenge Test

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Glucose Challenge Test

  • See Also
  1. Gestational Diabetes
  1. All pregnant patients at 24-28 weeks gestation
  2. Test with initial Prenatal Labs if indicated
    1. Overweight patient
    2. Family History of Diabetes Mellitus
    3. Age over 30 years
    4. Prior history of Glucose Intolerance
    5. Prior pregnancy complication
      1. Fetal Macrosomia
      2. Intrauterine Fetal Demise (Stillborn)
      3. Pregnancy Induced Hypertension (PIH)
      4. Polyhydramnios
      5. Congenital defect
  • Protocol
  1. Patient ingests 50 gram oral Glucose (e.g. Glucola Drink)
  2. Serum Glucose measured after 1 hour
  • Interpretation
  1. Serum Glucose >130 mg/dl (7.2 mmol/L) suggests gestation diabetes
  2. Obtain Glucose Tolerance Test 3 hour if positive
    1. Empiric Gestational Diabetes Management for GCT >200 mg/dl (without a 3 hour GTT)
  • Efficacy
  • Using cut-off of 130 mg/dl
  1. Test Sensitivity: 99% (85% if 140 mg/dl cut-off used)
  2. Test Specificity: 77% (86% if 140 mg/dl cut-off used)
  • References
  1. (2001) Obstet Gynecol 98:525-38 [PubMed]
  2. Moyer (2014) Ann Intern Med 160(6): 414-20 [PubMed]