Diabetes mellitus is one of the most common medical disorders during pregnancy, affecting approximately 3%–10% of women. Gestational diabetes mellitus accounts for 80%–90% of cases of diabetes mellitus in pregnancy, while preexisting type 2 diabetes accounts for approximately 10%– 20%. 1 Abnormal glucose metabolism results in persistent or postprandial elevation of blood sugar level. Elevation of blood sugar level during pregnancy is linked to suboptimal perinatal outcomes, including miscarriage, fetal malformations, stillbirth, and birth asphyxia. Diabetes mellitus is considered a major risk factor for abnormal fetal development. More women are expected to have diabetes mellitus during pregnancy due to older age at the time of conception, a growing rate of obesity, and the change in diagnostic criteria for gestational diabetes.