Intrapartum Glucose and Insulin Compared to Glucose Alone in Diabetic Women

About 2 to 9% of pregnant women are diagnosed with gestational diabetes. Peripartum complications attributed to diabetes include: birth trauma, neonatal hypoglycemia and hyperinsulinemia and neonatal hyperbilirubinemia. The incidence of neonatal hypoglycemia is about 40%. Strict glycemic control may lower the risk of neonatal complications. There is a lack of evidence on how to manage women with diabetes during labor. Previous studies recommended the use of intravenous saline solution boosted with 5% glucose and insulin as needed, glucose 5% with constant insulin infusion and others recommended the use lactated Ringer's solution. Most of these studies are either retrospective or have a small number of participants.

In this study we will examine the effect of 2 different protocols on glycemic control during labor and the immediate neonatal period. Women in group 1, will receive intravenous saline solution boosted with 5% glucose and constant insulin infusion. Women in group 2, will receive intravenous saline solution boosted with 5% glucose alone. The desirable intrapartum glucose level will be 70 to 100 mg/dL. Glucose levels will be checked hourly. Women in both groups will receive additional insulin infusion in cases of glucose levels above 100 mg/dL. Additionally, the 5% glucose solution will be substitute with lactated Ringer's solution in cases of glucose levels above 140 mg/dL.

Intravenous fluid regimens will be assigned according to a computer randomization sequence generation program. Women will randomly assigned to the 2 groups in a 1:1 ratio. The randomization sequence results will be kept in the delivery ward in a closed study box. Site investigators will enroll participants after confirming eligibility. The sequence will be concealed until intervention is assigned (and after obtaining a signed informed consent).

Our hypothesis is that 5% glucose combined with constant insulin infusion will achieve better glycemic control and thus will lead to lower rate of neonatal hypoglycemia. In order to detect a reduction of neonatal hypoglycemia from 40% to 20%, 182 women will be needed in both groups in order to achieve a level of significance of 95% (α, 2-sided = 0.05) and a power of 80% (β = 0.2).