Exploring Glycemic Variability and Time in Range: Emerging Indicators of At-Risk Pregnancy in Type 2 Diabetes Mellitus

A new study evaluated ambulatory glycemic profiles and glycemic variability in pregnant women with type 2 diabetes mellitus (T2DM) undergoing pharmacological treatment, compared to healthy pregnant controls––while examining their association with fetal outcomes.

This was a case-control study, conducted with 60 pregnant women in their third trimester, of which 40 had T2DM and 20 were non-diabetic controls. A flash glucose monitoring device was placed on the upper arm to assess ambulatory glucose profiles. Various glycemic metrics were analyzed and correlated with fetal outcomes in both groups.

For all women, 720 days of glucose data––comprising 69,120 readings––were reviewed. These included 46,080 glucose values from the T2DM group and 23,040 from the control group. Average glucose levels were higher in the T2DM group. Glycemic variability was significantly greater among those with T2DM, including the mean amplitude of glycemic excursions (MAGE) (52.85 mg/dL versus 35.72 mg/dL) and standard deviation (22.84 mg/dL versus 14.00 mg/dL). 

Of note, a MAGE exceeding 55 mg/dL was associated with adverse fetal outcomes, including large-for-gestational-age (LGA) infants, neonatal hypoglycemia, and stillbirth. Additionally, increased time above range (TAR) was linked to poor outcomes in the T2DM group. The LGA subgroup exhibited a higher TAR (15.2%) than those with normal fetal outcomes.

From the results, it was inferred that pregnant women with T2DM demonstrate increased glycemic variability relative to non-diabetic pregnant women. A MAGE above 55 mg/dL and elevated TAR are strongly associated with adverse fetal outcomes.

Source: Khurana V, Nigam A, De A. Internl J Gynec & Obst. 2025 Jan 4.