Insulins and oral hypoglycemic agents in pregnancy

Numerous studies have established a direct relationship between maternal levels of glycemic control and neonatal outcomes for pregnancies complicated by diabetes. The past several years have seen the addition of insulin analogues as well as many new oral agents to the pharmacological armamentarium available to treat diabetes. Insulin analogs (both rapid and long acting) are of potential interest for women with insulin-requiring diabetes because of the improved control reported in non-pregnant individuals. Insulin lispro is the only insulin analog to be systematically studied in pregnancy. At this time, the majority of evidence suggests that insulin lispro does not cross the placenta and does not have adverse maternal or fetal effects during pregnancy in women with diabetes. For women with gestational diabetes mellitus (GDM) and type 2 diabetes, which are characterized by insulin resistance and relatively decreased insulin secretion, treatment with oral hypoglycemic agents is generating much excitement. Most retrospective studies and the published clinical experience have failed to demonstrate an increased risk of neonatal hypoglycemia and other neonatal morbidities with glyburide or metformin. To date there has been only one randomized controlled trial utilizing glyburide, which found it to be safe and effective in the management of GDM. More intensive investigation regarding the safety and feasibility of oral agents in pregnancies complicated by type 2 diabetes is necessary.