Explanation
Gestational diabetes is typically asymptomatic but identified via a 1-hour 50g oral glucose challenge administered at 24-28 weeks of gestation. A venous plasma glucose blood level of > 140 mg/dL is suggestive, and must be confirmed with a 3-hour 100g oral glucose tolerance test. After administration of the 100g glucose challenge, at least two of the following are required for diagnosis: (1) fasting glucose > 95 mg/dL, (2) one-hour glucose >180 mg/dL, (3) two hour glucose >155 mg/dL, and (4) three hour glucose > 140 mg/dL.
Choice A -
To diagnose gestational diabetes, a positive 1-hour 50g oral glucose challenge must be followed up by a three-hour 100g oral glucose challenge. The diagnosis is only confirmed after both challenges are completed and the thresholds are met. Choice C - Following the diagnosis of gestational diabetes, the first step is strict glycemic control (fasting glucose).