Gestational Diabetes

Gestational diabetes is defined as carbohydrate intolerance of variable severity with onset during the present pregnancy. The definition applies regardless of whether insulin is used for treatment or the condition persists after pregnancy, but it does not exclude the possibility that glucose intolerance may have antedated the pregnancy.

The American College of Obstetricians and Gynecologists recommends that screening for gestational diabetes be done for women with one or more risk factors, including maternal age of 30 years or greater, family history of diabetes, previous macrosomic infant, previous stillbirth, previous malformed infant, obesity, hypertension, or glycosuria. The American Diabetes Association and the Centers for Disease Control and Prevention recommend screening all pregnant women between the twenty-fourth and twenty-eighth gestational week with a 50-g oral glucose challenge. A plasma glucose value of 140 mg per deciliter or greater 1 hour after a 50-g oral glucose dose indicates the need for a full diagnostic glucose tolerance test. It does not, by itself, establish the diagnosis. Diagnosis is based on results of the 100-g oral glucose tolerance test, interpreted according to the diagnostic criteria of O'Sullivan and Mahan (Table 372-1).

All patients with gestational diabetes are at significant risk for fetal macrosomia with consequent birth trauma, as well as other neonatal complications, including hypoglycemia, hypocalcemia, and hyperbilirubinemia.