Here's what I've found:
#1. The test is risky.
Hmm. Let's tell a pregnant woman to skip a meal and then drink a lot of sugar.
#2. The test result can be harmful.
Testing positive for gestational diabetes is more likely to bring risky interventions plus anxiety and less likely to encourage the nutritious diet that could actually make a difference.
Here's a quote from The Nourishing Traditions Book of Baby & Child Care:
"Ironically, this dangerous test is mostly reserved for pregnant women. For the rest of the population, the main test used is the 'casual plasma glucose test,' in which a sample of blood is drawn without regard to the time of the last meal or the content of that meal. You are not required to abstain from eating prior to the test nor take a highly sweetened drink - the very worst thing a diabetic can do, especially a pregnant diabetic." (69)Aviva Roma MD thoughtfully explores this in "Glucose Testing in Pregnancy: Should it Be Routine?"
"Aside from problems with food colorings and other potentially unhealthy ingredients in the glucola, which are actually small compared to the risks of untreated GDM, we need to consider the mental and emotional impact of a pregnant woman thinking of herself as having a 'disease' rather than just emphasizing the importance of a healthy diet and appropriate follow-up, perhaps with the exception of women whose blood sugar cannot be controlled with diet alone and who require medications."So are the risks worth the benefits? In what instances?