Maternal hyperglycemia is responsible for many fetal adverse outcomes. Ultrasound examination of these pregnancies aims at an early detection of congenital malformations, assessment of fetal well-being, and fetal growth. This evaluation will influence clinical decision in determining the best time and mode of delivery. We reviewed data from the literature on accuracy, usefulness, and indications of ultrasound examinations in pregnancies complicated with diabetes mellitus, whether pregestational or gestational.