Management of Preexisting Diabetes and Gestational Diabetes During Hospitalization

Preexisting diabetes and gestational diabetes mellitus (GDM) increase the risks of preeclampsia, preterm delivery, macrosomia, cesarean delivery, and neonatal hypoglycemia. In addition, women with preexisting diabetes have increased risk of diabetes-related complications, including exacerbation of diabetic retinopathy and nephropathy, hypoglycemia unawareness, diabetic ketoacidosis, and fetal demise. Therefore, accurate diagnosis and treatment of diabetes during pregnancy are essential to safe gestation and delivery. Prior to conception, those with gestational diabetes and type 2 diabetes are insulin resistant and have defects in insulin secretion, while those with type 1 diabetes are insulin deficient. During the late second and third trimesters, increases in placental growth hormone, as well as cytokines and inflammatory molecules, contribute to insulin resistance. The increase in insulin resistance over the course of gestation adds to the challenge of glycemic control. As articulated in the Pedersen hypothesis, inadequately controlled maternal glycemia results in fetal hyperinsulinemia and therefore increased growth, which is best measured by the fetal abdominal circumference. This chapter will review important considerations for patients with diabetes who are hospitalized during pregnancy.