It is very important to distinguish cases where pharmacological treatment is required as initial therapy:

The initial treatment of GDM includes medical nutrition and exercise. However, in cases where Glu intolerance is detected in early gestational age (<25w) or the fasting plasma Glu value is considered too high (>110mg/dL), medication should also be included in the initial treatment, as such cases are suspected for adverse outcomes if they are not immediately and efficiently treated. So:

Is Gestational age < 25^w or fasting plasma Glu > 110 mg/dl?