Diabetes mellitus (DM) is one of the most frequent metabolic complications associated with pregnancy, affecting both the prognosis of the pregnant woman and the newborn. Pregestational DM type 1 (T1DM) and type 2 (T2DM) and gestational DM (GDM) are associated with an increased risk of pregnancy complications such as miscarriage, fetal malformations, macrosomia, preeclampsia, and neonatal hypoglycemia, among others. The aim of this review was to evaluate the efficacy and safety of using the Dexcom G6 device (Dexcom, Co., USA) to continuously self-monitor blood glucose levels during pregnancy. This report was requested by the Spanish Ministry of Health.

We systematically searched for articles published to July 2021 in the MEDLINE, Embase, and Web of Science databases. We included experimental and observational primary studies addressing the safety, efficacy, and cost effectiveness of the Dexcom G6 device for gestational and pregestational diabetes.

Two non-comparative prospective studies were identified. One study of 25 pregnant women with T1DM, which evaluated glycemic control and complications during pregnancy and postpartum, reported stable hemoglobin A1c levels during gestation in women using the Dexcom G6 device. The percentage of time spent in the therapeutic glucose range (63 to 140 mg/dL) was 59 percent; 38 percent was in the hyperglycemic range and 3 percent was in the hypoglycemic range. Although some patients reported mild erythematous and edematous reactions to the sensor, no moderate or severe reactions or infections occurred at the sensor insertion site. The other study in pregnant women with T1DM (n=20), T2DM (n=3), or GDM (n=9) showed adequate accuracy of the Dexcom G6 device, compared with the reference method, especially when the sensor is placed on the arm.

Randomized controlled trials are required to assess the effectiveness and safety of the Dexcom G6 device in maintaining adequate glucose control during pregnancy in women with DM. Studies are also needed to compare the Dexcom G6 device with conventional capillary blood glucose self-monitoring or other monitoring methods. No cost-effectiveness studies have been conducted for the Dexcom G6 device in this patient population.