New GDM Diagnosis Criteria and Testing

International Association of Diabetes and Pregnancy Study Group have proposed new guidelines to test for GDM with a 2 hour 75 gr oral glucose tolerance test (OGTT).

GDM can be diagnosed if the woman exceeds any one of these glucose thresholds: fasting: more than 92 mg/dl (5.1 mmol), one hour: more than 180 (10.0 mmol) or two hours; 153 mg/dl (8.5 mmol).

The glucose level for diagnosis is now lower. Plus to diagnose GDM now only requires one, not two, elevated glucose results. As we know, some women who've not been diagnosed with diabetes prior to pregnancy learn they have diabetes (most often type 2) during pregnancy. The new guidelines refer to this as" overt diabetes.

The diagnostic criteria is identical to diagnosing diabetes in non-pregnant woman:

Fasting >126 mg/dl (7.0 mmol/l)
A1c > 6.5%, random > 200 mg/dl (11.1 mmol/l)

Obviously these women do not need to have an OGTT. They do need to be told they have and will continue to have type 2 diabetes after pregnancy. This is not GDM.
Source: EASD Lisbon Congress 2011
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