Do We Know How to Find Gestational Diabetes Mellitus?

It is now a common practice to identify women with gestational diabetes mellitus (GDM) and initiate treatment aimed at preventing hyperglycemic episodes and improving outcome for the woman and her unborn child(1)(2)(3). However, since before the 1st Workshop Conference on Gestational Diabetes Mellitus in 1979(4), there has been heated discussion about how this is best done. By the 4th international workshop in 1997(5), a compromise was agreed on that either of 2 protocols would be acceptable. The first protocol was to continue the previously recommended 50-g glucose challenge test with a diagnostic 3-h 100-g oral glucose tolerance test (OGTT) if the glucose concentration was increased at 1 h after the 50-g load. A diagnosis of GDM required that glucose thresholds be met or exceeded at 2 or more of the 4 time points during the 100-g test. In 1997, the only change to this protocol was that the cutpoints for glucose concentrations at each of the 4 time points were lower than previously recommended to reflect more accurately the change from measuring glucose in whole blood to measuring it in plasma(6). The second protocol was to administer a 2-h 75-g OGTT and, using the …