At Queens Hospital Center, Carpenter-Coustan criteria are used to diagnose GDM, with a first visit GCT and a third trimester GCT if the first is normal. Can we identify patients at risk of GDM, with a goal of optimizing GDM, and establishing a cutoff GCT value for rescreening patients with a normal early GCT?METHODS:
A retrospective chart review yielded 246 subjects who were classified as follows: Group 1: Both first visit and 3rd trimester GCT normal, Group 2: Normal initial GCT, abnormal 3rd trimester GCT; Group 3: Abnormal Initial GCT. Age, parity, BMI, initial GCT values, and prior glucose intolerance were compared among groups.RESULTS:
Group 3 was significantly older than Group 1 but there was no difference between Groups 2 and 3. BMI did not differ, P=.065. Although mean GCT of Group 1 significantly differed from Group 2, the range of GCT values were overlapping (65–135) and (75–134). Within Group 1, no patients had a prior glucose intolerance developed GDM in this pregnancy. In Group 2, 33% of the subjects developed GDM; meanwhile in Group 3 54% of the subjects developed GDM. Overall, there was a 60% of occurrence of GDM after initial screening in those with a history of glucose intolerance.CONCLUSION:
Subjects with a history of glucose intolerance should be screened at the first visit with a 3-hour GTT, given the very high rates of GDM in these patients. An early initial GCT cut-off value for lower risk subjects could not be determined.