Continuous Glucose Monitoring System Profile of Women Stratified Using Different Levels of Glycated Hemoglobin (HbA1c) in Early Pregnancy: A Cross-sectional Study.

Abstract

To evaluate the differences in the continuous glucose monitoring system (CGMS) profiles of women in early pregnancy stratified based on different HbA1c levels known to be predictive of gestational diabetes mellitus (GDM) at 24-28weeks of gestation (≥ 5.2%) and adverse pregnancy outcomes (≥ 5.5%) in Indian women. We enrolled women at 8+ 0 to 19+ 6weeks of gestation (early pregnancy), evaluated the glycaemic parameters of clinical interest using CGMS, and reported them per standard methodologyproposed by Hernandez et al. WHO 2013 criteria were used for diagnosis of early GDM. Ninety-six women were enrolled at 14.0 ± 3.2weeks of gestation. Of these, 38 were found to have early GDM (diagnosed before 20weeks of gestation) on evaluation. Of 96 women, 33 (34.4%) had HbA1c value ≥ 5.5% [11 (19.0%) with normoglycaemia and 22 (57.9%) with GDM]. The women with elevated HbA1c differed significantly from those with HbA1c < 5.5% for all evaluated parameters. The differences for overall women were > 10mg/dl (0.56mmol/l) for 1-h postprandial glucose (difference of 0.78mmol/l), 2-h postprandial glucose (difference of 0.59mmol/l), peak postprandial glucose (difference of 0.75mmol/l), and 1-h postprandial glucose excursion (difference of 0.59mmol/l). Of 58 women with normoglycaemia, 29 (50.0%) had an HbA1c value ≥ 5.2%. In comparison, in the normoglycaemic group of women with and without HbA1c ≥ 5.2% (known to be predictive of future GDM), the results were significant for 1-h (difference of 0.44mmol/l), 2-h (difference of 0.278mmol/l), and peak postprandial glucose (difference of 0.35mmol/l). The results suggest that women with elevated HbA1c (≥ 5.5%) in early pregnancy significantly differ from those with HbA1c < 5.5% in all glycaemic parameters evaluated in this study, suggesting that HbA1c at this cut-off has a role to play in early pregnancy.