Exploring glycemic variability and time in range: Emerging indicators of at‐risk pregnancy in type 2 diabetes mellitus

OBJECTIVE: This study compares ambulatory glycemic profile and glycemic variability between pregnant women diagnosed with type 2 diabetes mellitus (T2DM) receiving pharmacotherapy and healthy pregnant women without diabetes and assesses their correlation with fetal outcome. METHOD: This was a case-control study involving 60 pregnant women (40 with T2DM and 20 healthy controls) in the third trimester of pregnancy. A flash glucose monitor device was applied over the upper arm to obtain the ambulatory glucose profile. Various glycemic parameters were analyzed and correlated with fetal outcomes among the two groups. RESULTS: A total of 720 days of glucose data, comprising 69 120 data points, were analyzed. This included 46 080 glucose values from the T2DM group and 23 040 from the healthy control group. Mean glucose levels in the T2DM group were 23.75% higher compared to the controls. All measures of glycemic variability were significantly elevated in the T2DM group, including mean amplitude of glycemic excursions (MAGE) (52.85 mg/dL vs. 35.72 mg/dL, P = 0.036) and standard deviation (22.84 mg/dL vs. 14.00 mg/dL, P = 0.029). A MAGE >55 mg/dL was associated with adverse fetal outcomes, such as large-for-gestational-age (LGA) infants, neonatal hypoglycemia, and stillbirth. In the T2DM group, poor outcomes were also linked to a higher time above range (TAR) (13.39% vs. 2.5%, P = 0.0001). The LGA subgroup exhibited an elevated TAR (15.2%) compared to those with normal outcomes. CONCLUSION: Pregnant women with T2DM exhibit higher glycemic variability compared to healthy pregnant women. A MAGE >55 mg/dL was associated with adverse fetal outcomes, and elevated TAR significantly influenced these outcomes.