Continuous glucose monitoring during pregnancy complicated by gestational diabetes mellitus

Postprandial glucose has been reported to be the best predictor of neonatal macrosomia. Therefore, self-blood glucose monitoring (SBGM) protocols for diabetic pregnant women stress the importance of measuring blood glucose after meals. However, there is controversy in the literature. Traditionally, glucose monitoring has been prescribed at 2 hours after eating to coincide with the times a patient is at increased risk of hypoglycemia. Human regular insulin peaks at 2 to 3 hours after injection; thus, checking blood glucose at the 2-hour point is a relic of strategies to prevent hypoglycemia. In pregnancy, the emphasis has been on measuring during times when blood glucose levels are highest. One hour after the start of the meal has been shown to be the time of peak postprandial response in 90% of pregnant woman. Because glucose excursions may reach their maximum at varying times, based on the size and number of meals ingested, SBGM alone may not capture the full extent of total daily postprandial hyperglycemia. Because intermittent blood glucose monitoring underestimates the number of hyperglycemic events, a more accurate determination of postprandial glucose levels is necessary to decrease the risk of macrosomia in gestational diabetes mellitus. Continuous glucose monitoring may facilitate the detection of all postprandial peaks, including those due to unscheduled meals, and may provide an opportunity for better intervention by providing the complete glucose profile.