The criteria for the diagnosis of GDM are based on the original work of O’Sullivan and Mahan and modified by Carpenter and Coustan (see section on Gestational Diabetes). Risk assessment for GDM is undertaken at the first prenatal visit. Women with risk factors, including marked obesity, personal history of GDM in prior pregnancy, glycosuria, or strong family history, should have a glucose tolerance test (GTT) as soon as feasible. If results of testing do not demonstrate diabetes, they should be retested between 24 and 28 weeks’ gestation. A fasting plasma glucose of greater than 126 mg/dL or a casual level of greater than 200 mg/dL meets the criteria for diabetes if confirmed on a subsequent day.
Evaluation of low-risk women during pregnancy takes place between 24 and 28 weeks’ gestation and typically follows a two-step approach. An initial screening is a blood glucose concentration 1 hour after the patient takes a 50-gram oral glucose load. A value of greater than 140 mg/dL identifies approximately 80% of women with GDM. If a screening value is greater than 190 mg/dL, a fasting blood glucose should be checked on a subsequent day. A subsequent fasting value of ?
There are also studies which indicate that protein intakes at the lower end of the recommendation may have advantages in people with diabetes with renal changes. In people with evidence of clinical diabetic nephropathy a protein restriction to <0.6 g/kg/day can reduce the elevated GFR and albuminuria. In people with persistent proteinuria a similar protein restriction has been shown to modify the progression of the disease. There is no conclusive evidence about the different properties of animal or vegetable proteins and their effect on diabetic renal disease. The recommendation for protein intake for people with diabetes is that it should range between 10 and 20% of total energy.