The use of HbA_1c as an aid in the diagnosis of gestational diabetes mellitus

Abstract

The ability of HbA_1c was evaluated in the diagnosis of gestational diabetes mellitus (GDM) and for the implications of its use in clinical practice. A total of 339 pregnant women with an estimated gestational age of 24–28 weeks were evaluated for GDM using an oral glucose tolerance test (OGTT) based on International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria. A ROC curve was drawn to determine the sensitivity and specificity of HbA_1c in detecting GDM. An HbA_1c cut-off value of ≥ 5.2% had sensitivity of 64.15% and specificity of 67.48% in diagnosing GDM, and a positive predictive value of 26.77%. Using two cut-offs in the ‘rule-in and rule-out’ algorithm, 94.4% of the GDM cases would have been detected but 33% (43 of the 130) women would had been misclassified. HbA_1c is not suitable to use alone for the diagnosis of GDM and is not useful in decreasing the need for OGT testing.

Keywords::

• Gestational diabetes mellitus
• HbA_1c
• OGTT

Acknowledgement

The authors appreciate the contributions and editorial assistance made by S. Delacroix.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.