Gestational Diabetes Mellitus

Normal pregnancy is a state of insulin resistance. To spare glucose for the developing fetus, the placenta produces several hormones that antagonize maternal insulin, shifting the principal energy source from glucose to ketones and free fatty acids. Most pregnant women maintain normal blood glucose levels despite the increased insulin resistance through enhanced insulin production and release by the pancreas, both in the basal state and in response to meals. Gestational diabetes mellitus is a state of carbohydrate intolerance that develops or is first recognized during pregnancy. In some women, β-cell production of insulin cannot keep pace with the resistance to insulin produced by the diabetogenic hormones from the placenta. The prevalence of gestational diabetes mellitus in the USA is 2-5%, and is proportional to the prevalence of type 2 diabetes in the population under examination, because they share a similar pathophysiology. The prevalence of gestational diabetes mellitus, along with the prevalence of type 2 diabetes, appears to be increasing. It is the most common medical complication of pregnancy and is clearly linked to several maternal and fetal complications including fetal macrosomia with operative delivery and birth trauma, preeclampsia and hypertensive disorders, metabolic complications in the neonate including hypoglycemia, hypocalcemia, and hyperbilirubinemia, prematurity, and perinatal mortality.