The Epidemiology of Diabetes Interventions and Complications study, a prospective observational follow-up of the Diabetes Control and Complications Trial cohort, reported persistent benefits for micro- and macro-vascular complication in type 1 diabetes mellitus with intensive insulin therapy. It is the standard of care for most patients with type 1 diabetes. There are two modalities: continuous subcutaneous insulin infusion (CSII), so called insulin pump, and multiple dose of insulin. Both shows similar effects in frequency of severe hypoglycemia and progression of microvascular disease, but CSII provides slightly better in glycemic control. An important aspect of intensive insulin therapy is educating patients about basal insulin, and carbohydrate/insulin ratio, sensitivity index, the coordination of meals, activity, stress, and hormonal changes with frequent monitoring of blood glucose levels during pregnancy. It is important to identify and resolve emotional and attitudinal barriers of the patient and family for improving glycemic control during intensive diabetes management.