Glucose and insulin requirements during labor and delivery: the case for normoglycemia in pregnancies complicated by diabetes.

OBJECTIVE: To present protocols for maintaining normoglycemia during labor and delivery in order to achieve optimal outcomes of pregnancy in women with diabetes.
RESULTS: Labor has a glucose-lowering effect. In the case of women with insulin-requiring gestational diabetes, no additional insulin is needed with the onset of labor; sufficient glucose should be infused to keep such women from becoming ketotic from the pronged period of starvation. Likewise, protocols derived from glucose-controlled insulin infusion studies reveal that women with type 1 diabetes require no more subcutaneously administered insulin on the morning of an induction of labor or at the onset of spontaneous labor. The intravenously administered solutions should be started with isotonic saline or electrolyte solutions. As soon as active labor is achieved, the solutions should be switched to a glucose-containing fluid and administered at a rate of 2.55 mg/kg per minute.
CONCLUSION: Labor is a form of exercise and thus obviates the insulin requirement in women with all types of diabetes, but it also necessitates an eightfold increase in glucose substrate in order to prevent maternal hypoglycemia and ketosis. The literature presents clear evidence that neonatal hypoglycemia is directly related to maternal hyperglycemia during labor and delivery. Thus, protocols for maintaining normoglycemia during labor and delivery are necessary to achieve optimal results.