Diagnosis of gestational diabetes mellitus in China.

After the publication of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study (1), the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) (2) formulated consensus guidelines for the testing and diagnosis of gestational diabetes mellitus (GDM). These have been adopted by the American Diabetes Association (3). The Ministry of Health (MOH) of China also recommended that new testing and diagnostic criteria based on the IADPSG guidelines (4) be effective beginning 1 December 2011. The Chinese criteria agree with the American Diabetes Association that a diagnostic 75-g oral glucose tolerance test (OGTT) should be performed between the 24th and 28th week of gestation for all pregnant women not previously known to have diabetes. A diagnosis of GDM can be made if one or more of the following glucose levels are elevated: fasting ≥5.1 mmol/L, 1 h ≥10.0 mmol/L, and 2 h ≥8.5 mmol/L.

This is the one-step approach that the MOH has recommended to well-resourced medical institutions. However, in China a formal OGTT may be difficult to implement in low-resourced rural areas. Therefore, and different from the American Diabetes Association, the MOH has recommended a two-step approach under these circumstances. A fasting plasma glucose can be used as a screening tool to reduce the number of OGTTs required. If the fasting plasma glucose is ≥5.1 mmol/L, GDM can be diagnosed and if <4.4 mmol/L, GDM is unlikely. Women with a result of ≥4.4 and ≤5.0 mmol/L will still require a glucose tolerance test. This approach will approximately halve the number of glucose tolerance tests required (5).