Gestational Diabetes Mellitus (GDM): Comparative Evaluation of Two Treatment Regimens, Diet Versus Insulin and Diet

Two-hundred and two pregnant women with impaired glucose tolerance were randomized to treatment with diet or diet and insulin by stratified selection. Self-monitoring of blood glucose was performed six times a day, 3 days/wk. Dietary treatment was considered inappropriate if fasting and postprandial blood glucose values exceeded 7 and 9 mmol/L, respectively, in which case insulin therapy was instituted. Insulin doses were adjusted according to blood glucose values, aiming at fasting and postprandial values below 5 and 6.5 mmol/L, respectively. There were no perinatal deaths. The two treatment regimens disclosed no differences regarding achieved degree of maternal blood glucose control, hemoglobin A_1c at delivery, obstetric or neonatal complications, infant's size at birth including skinfold thickness, or C-peptide concentration in cord serum. Routine treatment of pregnant women with mild carbohydrate intolerance with insulin seems unnecessary. However, 15 patients (14%) in the diet group needed insulin to achieve acceptable blood glucose control, underlining the importance of monitoring blood glucose to detect those who are at risk of developing overt diabetes.