Effect of a Continuous Glucose Monitoring on Maternal and Neonatal Outcomes in Gestational Diabetes Mellitus: A Randomized Controlled Trial

Introduction

Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance first diagnosed during pregnancy [1]. It is associated with adverse pregnancy outcome for the mother, and the fetus with consequences regarding future health and development of the neonate. Maternal consequences include increased rate of operative and cesarean delivery, hypertensive disorders during pregnancy and future risk for type 2 diabetes mellitus (T2DM) as well as other aspects of the metabolic syndrome, such as obesity, cardiovascular morbidities and recurrent GDM [2-4]. Also, children born to mothers affected by gestational hypertension have been found to have higher body mass index (BMI), systolic blood pressure, glucose and insulin levels [5]; this risk extends into adulthood, with an 8-fold increased risk of type 2 diabetes among young adults exposed to gestational diabetes during fetal life [6].

Of all types of diabetes, GDM accounts for approximately 90-95% of all cases [4, 7]. It complicates up to 14% of all pregnancies. Its prevalence is increasing and parallels the rising incidence of type 2 diabetes mellitus worldwide [3,4]. Risk factors for developing GDM in pregnancy include obesity, previously GDM, glycosuria, family history, ethnicity and hypertension [5,6].

It has been clearly demonstrated that intensified management and the achievement of established levels of glycemic control using memory-based self-monitoring blood glucose, glyburide treatment or if needed multiple injections of insulin, diet, and an interdisciplinary team effort was associated with enhanced pregnancy outcome [8-10]. The above recommendations support the routine use of self-monitoring blood glucose in the management of the pregnancy compromised by diabetes. The recommendation of the American Colleague of Obstetrics and Gynecology as recently published [11] are four-times daily glucose monitoring preformed as fasting and either 1 or 2 hours after each meal with possible modifications made in diet-controlled GDM patients after reaching well controlled glucose levels.

The role of self-monitoring blood glucose in intensified therapy in non-pregnant and pregnant women has become the standard to achieve targeted levels of glycemic control. Yet, self-monitoring blood glucose may have some disadvantages. It is painful to perform. Another shortcoming in the use of reflectance meters is that each glucose determination represents a sole glucose value during the day, a "snap shot" of glucose value.