diagnostic criteria for diabetes mellitus
the criteria for the diagnosis of diabetes are shown in table 2.
three way to diagnose diabetes are possible, and each, in the absence of unequivocal hyperglycemia,must be confirmed,on a subsequent day,by any one of the three methods given in Table 2. The use of the hemoglobin A1C for the diagnosis of diabetes is not recommended at this time.
diagnosis of GDM
The criteria for abnormal glucose tolerance in pregnancy are those of Carpenter and Coustan (3). Recommedations from the American Diabetes Association's Fourth International Workshop Conference on Gestational Diasbetes Mellitus held in March 1997 support the use of Carpenter/Coustan diagnostic criteria as well as the alternative use of a diagnostic 75 g. 2hr. OGTT. These criteria are summarized below.
Testing for gestational diabetes. Previous recommendations included screening for GDM performed in all pregnancies.
However, there are certain factors that place women at lower risk for the development of glucose intolerance during pregnancy, and it is likely not cost effective to screen such patients.Pregnant women who fulfill all of these criteria need not be screened for GDM. This low-risk group comprises women who
-are 126 mg/dl(7.0 mmol/l) meets the threshold for the diagnosis of diabetes . In the absence of unequivocal hyperglycemia, the diagnosis must be confirmed on a subsequent day. Confirmation of the diagnosis precludes the need for any glucose challenge. In the absence of this degree of hyperglycemia,evaluation for GDM in women with average or high-risk characteristics should follow one of two approaches.
One-step approach. Perform a diagnostic OGTT without prior plasma or serum glucose screening. The One-step approach may be cost-effective in high risk patients or populations (e.g., some Native American group)
Two-step approach. perform an initial screening by measuring the plasma or serum glucose concentration 1hr. after a 50g. oral glucose load (glucose challenge test GCT) and perform a diagnostic OGGTT on that subset of women exceeding the glucose threshold value on the GCT. When the two-step approach is used, a glucose threshold value >140 mg/dl(7.8 mmol/l) identifies 80% of wo