Diabetes in pregnancy confers a number of risks for both the mother and her baby, and many of these risks are encountered in the labor and delivery unit. The obstetric provider caring for women with diabetes should be alert to the risk of hypertension and the potential for difficult delivery due to an overgrown fetus. Women with preexisting diabetes or poor glycemic control are at increased risk for poor obstetrical outcomes such as stillbirth or delivery of a malformed infant. Meticulous attention to avoiding maternal hyperglycemia during labor can prevent neonatal hypoglycemia. © 2007 Elsevier Inc. All rights reserved.