Gestational diabetes: an alternative, patient-friendly approach for using the diagnostic 100-g OGTT in high-risk...

To simplify the 100-g oral glucose tolerance test (OGTT) for making a diagnosis of gestational diabetes mellitus (GDM).

During a 6-year period, 6,801 pregnant women underwent the 3-h, 100-g OGTT in a high-risk, multiethnic population. All these women had either a positive glucose challenge test/clinical history or were part of a universal screening protocol. The area (AUC) under the receiver-operating characteristic curve was used to compare the performance of the fasting plasma glucose (FPG), 1-h, 2-h and 3-h glucose values for GDM diagnosis. Ideal cut-offs of the best performing glucose value alone and in combination were used to find the best predictor for GDM with minimal loss of sensitivity and specificity.

Using the American Diabetes Association criteria, 2,127 (31.3%) women were classified as having GDM. The 2-h value was the best performing (AUC 0.933) glucose value; at an optimal cut-off of >or=8.6 mmol/l, the sensitivity was 83.6% with a specificity of 92.8%. It did not achieve sufficient collective specificity and sensitivity at various thresholds to be useful. However, in combination with FPG (either FPG >or=5.3 mmol/l or 2-h >or=8.6 mmol/l) or (either FPG >or=5.6 mmol/l or 2-h >or=8.6 mmol/l), the sensitivity/specificity were 98.5%/84.7% and 92.5%/89.3%, respectively.

An abbreviated 100-g OGTT, using only the FPG and 2-h glucose value, may be a useful alternative in high-risk populations to make a diagnosis of GDM by being cost-effective and patient-friendly.