title: Early-pregnancy glucose screening for gestational diabetes mellitus.
abstract: OBJECTIVE
  To determine the accuracy of the 50-g, one-hour glucose screening test administered at 16 weeks of pregnancy for identifying women with gestational diabetes mellitus.
  
  
  METHODS
  Two hundred fifty-five women underwent 50-g, one-hour glucose screening tests at 16 weeks of pregnancy. Those with results > or = 135 mg/dL underwent 100-g, three-hour glucose tolerance tests. All patients without diagnoses of gestational diabetes during the second trimester of pregnancy underwent standard third-trimester glucose testing.
  
  
  RESULTS
  Gestational diabetes mellitus was diagnosed in 25 patients. Glucose screening tests administered at 16 weeks of pregnancy identified 96% (24) of these patients. Patients with 16-week glucose screening test results > or = 135 mg/dL had a 55% risk of developing diabetes during pregnancy, while the risk was 0.6% for patients with 16-week test results < or = 110 mg/dL. Patients with 16-week glucose screening test results in the intermediate range, 111-134 mg/dL, had a 4.8% risk of developing diabetes during pregnancy.
  
  
  CONCLUSIONS
  Glucose screening at 16 weeks of pregnancy is a useful alternative to third-trimester screening for gestational diabetes. The negative predictive value of screening test results < or = 110 mg/dL is 99.4%. The positive predictive value for screening test results > or = 135 mg/dL is 55%. This latter finding is superior to the 8.6-22% found during the third-trimester.
authors.affiliation: Departments of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina, USA. nahum001@mc.duke.edu
authors.forename: Gerard G
authors.initials: GG
authors.lastname: Nahum
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilson
authors.forename: Harold
authors.initials: H
authors.lastname: Stanislaw
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005865:Gestational Age; D005951:Glucose Tolerance Test; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood; D011262:Pregnancy Trimester, Second / Q000097:blood; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D001786:Blood Glucose