Insulin therapy in pregnancy complicated by diabetes: are insulin analogs a new tool?

It has been demonstrated that good metabolic control maintained throughout pregnancy can reduce maternal and fetal complications in diabetes. To achieve good metabolic control, before conception and throughout pregnancy, insulin therapy needs to be optimized, and, in this context, the new insulins currently on the market may help. We therefore review here what is known about the potential benefits and risks related to the use of these new insulins in pregnancy. Clinical and experimental data on insulin lispro strongly suggest that lispro does not have adverse maternal or fetal effects during pregnancy in women with preexisting diabetes, and also that its use in these women results in improved glycemic control, fewer hypoglycemic episodes, and improved patient satisfaction. In women with gestational diabetes mellitus (GDM), the use of insulin lispro is efficient in reducing postprandial hyperglycemia and some neonatal features related to hyperglycemia, thus stressing its usefulness in this condition. As for insulin aspart, clinical data on GDM patients shows the same efficacy as insulin lispro in lowering postprandial hyperglycemia, indicating that insulin aspart may be used in GDM when this condition is characterized by postprandial hyperglycemia. The results of a multicentric study now in progress on the efficacy and safety of insulin aspart in type 1 pregnant diabetic patients will definitely be useful in establishing whether this insulin is safe in pregnancy. For the moment, the use of insulin glargine during pregnancy is not recommended owing to the lack of data on maternal and fetal effects.