Introduction: Continuous glucose monitoring (CGM) is an emergent technology in the management of gestational diabetes mellitus (GDM). It records a complete glycaemic profile and hence reveals glucose fluctuations and trends otherwise undetected by standard monitoring. This information has shown to improve glycaemic control and pregnancy outcomes. An important knowledge gap in the utility of CGM is its use in predicting GDM and hence the aim of this study was to explore the potential use of CGM as a screening tool.
Methods: A prospective observational study was conducted at the Royal Hospital for Women between May-August 2015. Pregnant women who were diagnosed with GDM or were willing to have CGM before their glucose tolerance test (OGTT) were recruited. The glycaemic reports generated by CGM for each patient were analysed to calculate measures of glycaemic variability. Acceptability of CGM was measured using a questionnaire. Accuracy of CGM was assessed in comparison to the OGTT.
Results: 37 women completed CGM and of these, 28 were diabetic and 9 were normoglycaemic. Women with GDM had a significantly higher mean (p = 0.045), standard deviation (p = 0.02), mean amplitude of glycaemic excursions (p = 0.046) and mean of daily differences (p = 0.003) than the normoglycaemic women.
CGM was acceptable, safe and well tolerated among all women. It was accurate, displaying a strong positive correlation with the OGTT which was statistically significant, (rs= 0.92, p<0.0001). Additionally, CGM revealed otherwise undetected glucose aberrations in 7 of 9 women who were deemed normoglycaemic by the OGTT.
Conclusion: The results of this pilot study highlight the promise of CGM in screening for GDM. Further study is required to explore these findings.