Are patients with positive screening but negative diagnostic test for gestational diabetes under risk for adverse pregnancy outcome?

OBJECTIVE: Our aim was to determine the obstetrics outcomes of patients with positive 1-h glucose challenge test (GCT), but negative diagnostic test for gestational diabetes.
METHODS: Pregnancy records of 409 pregnants were reviewed. Patients were screened for gestational diabetes mellitus (GDM) with one-hour 50 g glucose challenge test (GCT) at 24-28 weeks of gestation. Patients with glucose challenge tests values > or = 130 mg/dL were refered for the 3 h, 100-g oral glucose tolerance test (OGTT). Positive GCT but negative for OGTT group (Group A) were compared retrospectively with the group of negative GCT (Group B) for obstetrics outcomes. RESULT: GDM and impared glucose tolerance (IGT) were diagnosed in 33 (7.6%) and 46 (10.5%) patients, respectively. We identified 141 (34.4%) patients with positive GCT but negative for OGTT (Group A) and 189 (46.2%) patients with negative GCT (Group B). Gestational weight gain, polyhydramnios, family history of diabetes mellitus were significantly higher in group A than group B (P < 0.05). Prevalance of preterm labor, hypertension, cesarean delivery, mean birthweight, proportion of babies admitted to neonatal intensive care unit were similar in both groups.
CONCLUSION: There are some differences for pregnancy outcomes between pregnants with positive GCT but negative for OGTT and negative GCT. These patients should be followed up carefully during the antepartum and intrapartum period.