title: Criteria for screening and diagnosis of gestational diabetes mellitus in the first trimester of pregnancy.
abstract: OBJECTIVE
  To propose new cutoffs in plasma glucose levels in screening and diagnosis of gestational diabetes mellitus (GDM) in the first trimester of pregnancy.
  
  
  METHODS
  A 50-gram oral glucose challenge test (GCT) was performed in 1,716 singleton pregnancies at 6-14 weeks' gestation. In those with a positive GCT, a 100-gram glucose tolerance test (GTT) was carried out. The GCT and as necessary the GTT were repeated at 20-30 weeks. The relation of the results of the GCT and GTT at 6-14 weeks to that at 20-30 weeks was examined.
  
  
  RESULTS
  The diagnosis of GDM was made in 85 cases. In the GCT, there was a significant association between 1-hour plasma glucose levels at 6-14 weeks and at 20-30 weeks (r = 0.558, p < 0.0001), and in all cases of GDM, the level was 130 mg/dl or more at 6-14 weeks and 140 mg/dl or more at 20-30 weeks. In the GTT, the plasma glucose 1, 2 and 3 h after the 100-gram glucose load at 6-14 weeks was, respectively, 18, 29 and 35% lower than at 20-30 weeks.
  
  
  CONCLUSIONS
  Effective diagnosis of GDM in the first trimester can be achieved by lowering the GCT and GTT plasma glucose cutoffs.
authors: Hospital Universitario Materno-Infantil de Canarias, Las Palmas, Spain.
authors: Walter
authors: W
authors: Plasencia
authors: Raquel
authors: R
authors: Garcia
authors: Susana
authors: S
authors: Pereira
authors: Ranjit
authors: R
authors: Akolekar
authors: Kypros H
authors: KH
authors: Nicolaides
mesh_terms: D000328:Adult; D001786:Blood Glucose; D002985:Clinical Protocols; D016640:Diabetes, Gestational / Q000175:diagnosis*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D018579:Patient Selection; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*
chemical_list: D001786:Blood Glucose