Utility of Glycated Haemoglobin in Gestational Diabetes Mellitus: Present and Future

Gestational diabetes mellitus (GDM) is a major public health problem with various complexities involved in its diagnosis. Traditionally an oral glucose tolerance test is used for the diagnosis of GDM, however the measurement of plasma glucose values both after fasting and the glucose challenge test has certain shortcomings, especially during pregnancy. The American Diabetes Association (ADA) in 2010 and the World Health Organization (WHO) in 2011 have accepted glycated haemoglobin (HbA1c) as a tool for diagnosing diabetes mellitus, however it is not currently recommended as a diagnostic tool for GDM. The estimation of HbA1c levels is likely to be more acceptable to pregnant women, as a single non-fasting blood sample is required for this investigation. Although various studies have shown different HbA1c cut-off values representing the best equilibrium between sensitivity and specificity for GDM, most of them conclude that an HbA1c level of >5.95% can be used to diagnose GDM in pregnant women with high specificity. This article reviews the present role and future place of measuring HbA1c levels in the diagnosis of GDM.