It is self-evident that women with type 1 and type 2 poorly controlled diabetes have a significant increase in adverse perinatal outcome in comparison to nondiabetic patients. The condition is especially detrimental when the targeted level of glycemia is not achieved. It is also realistic to assume that similar adverse outcomes will result in gestational diabetes mellitus (GDM) since it is a looking-glass image of type 2 diabetes. Since the late 1960s when O’Sullivan first suggested the term “gestational diabetes,” an argumentative environment has persistently surrounded this clinical entity and its association to adverse pregnancy outcome, i.e., macrosomia, birth trauma, and metabolic complications. However, opinions and anecdotes have surpassed research-generated data.