Diabetes mellitus is a chronic metabolic disease with absolute or relative blood insulin deficit that results in hyperglicemia and glycosuria, increase in protein and fat catabolism and tendency to ketoacidosis. During pregnancy carbohydrate metabolism is affecter by the fetus (who cosumes maternal glucose and aminoacids), placental hormones (IICS, estrogens, progesterone) and cortisol, all having antiinsulinic effects. Gestational diabetes occurs in 3 to 6 per cent of pregnancies and is associated to macrosomy, birth trauma, cesarean section, and neonatal hyperbilirrubinemia, hypocalcemia and hypoglicemia. Diabetes mellitus complicates 0.1 - 0.5% of pregnant women and increases the incidence of spontaneous abortionm pregnancy induced hypertension, hydramnios, intrauterine fetal growth retardation, macrosomu, malformations and perinatal mortality. With insulin discovery and modern manage...