Diabetes in pregnant women is associated with an increased risk for maternal and neonatal morbidities and remains a significant medical challenge. Fortunately, the prognosis has changed dramatically, related to an increased clinical awareness of the potential risks for the mother and the infant, better health care and intensive treatment strategies to maintain the closest to normal metabolic milieu. Diabetes and pregnancy may be divided into pregestational diabetes (women previously diagnosed with type 1 or type 2 diabetes) and gestational diabetes defined as any glucose intolerance detected during pregnancy that has evolved from a diagnosis associated with the metabolic risk of type 2 diabetes to a clinical condition associated with higher risks for maternal and perinatal morbidity. Early diagnosis of gestational diabetes is an important step to improve outcomes and systematic or selective screening with the OGTT should be established. Associated with the global epidemic in diabetes, pregnancy associated with diabetes is saturating high-risk obstetric clinics and neonatal intensive care units, becoming a heavy burden to the health care systems around the world.