Objective: A controversy exists regarding the time to monitor blood glucose in the diabetic pregnancy (60 or 120 minutes after meals). Using a novel approach that provides continuous measurement of blood glucose, we sought to determine postprandial glucose profile in the diabetic pregnancy.
Study design: Subjects were connected to a continuous glucose monitoring system for 72 consecutive hours. A continuous glucose monitoring system measures the interstitial glucose levels in subcutaneous tissue every 5 minutes. Women were instructed to record the time of each meal during the study period. For each meal, the first 240 minutes were analyzed.
Results: Sixty-five women participated in the study: 26 women were treated by diet alone; 19 women received insulin therapy, and 20 women had type 1 diabetes mellitus. The time interval from meal to peak postprandial glucose levels was similar in all the evaluated types of diabetic pregnancies and in good and poor control insulin-treated patients with gestational diabetes mellitus (approximately 90 minutes). Failure to return to preprandial glucose values within a 3-hour observation period was identified in approximately 50% of the patients. A similar postprandial glucose peak time was obtained for breakfast, lunch, and dinner in all study groups. Postprandial hypoglycemia events were noted in approximately 10% of the meals and occurred about 160 minutes after mealtime.
Conclusion: The time interval for postprandial glucose peak in diabetic pregnancies is approximately 90 minutes after meals throughout the day and is not affected by the level of glycemic control. This information should be considered in the treatment of diabetes mellitus in pregnancy.