Gestational diabetes is considered as a carbohydrate intolerance, first diagnosed during pregnancy. A previous stage of carbohydrate impairement may precede its abnormality; therefore it may be convenient to establish some management in order to avoid the gestational diabetes. Six pregnant women who had moderate elevated level of blood glucose at fasting and postprandial were treated with acarbose, alpha-glucosidase inhibitor agent, given three times a day before meals. In all patients fasting and postprandial glucose levels were normalized; pregnancies went uneventful and the newborns were considered normal. Acarbose was associated with intestinal discomfort which persisted during the whole pregnancy.