I don't. Ask your ob for the research, and I will be happy to go over it for you.
I can say this, though: the problem with all tests of fetal well-being is their high false-positive rates, that is, the test says there is a problem, but there really isn't. In a healthy woman, which you are if your GD is under control--or even in a woman with moderate problems--the test is much more likely to be wrong than right if it says there is a problem. But no one is going to sit on their hands with a test result that says the baby is in trouble, so women who have tests of fetal well-being are not infrequently going to end up with labor inductions, cesarean surgeries, or both that they didn't need. Add on to that the false-negative rate: the test says everything is fine when it isn't. It is also possible to have a true positive where delivering the baby won't solve the problem. In fact, it is also possible for a compromised baby to be able to tolerate normal labor but not induced labor where contractions can be longer, stronger, and closer together. Even a healthy baby can be distressed who wouldn't have been with natural contractions. (This, of course, just reinforces the medical model approach. "Thank goodness we intervened," everyone says, it never occurring to them that intervening was what caused the baby to go into distress.) In short, the odds are 99.9% that your baby will live through the next four days whether you have the stress test or not, and you could end up with a cesarean that you didn't really need and, ironically, that puts you, your baby, and future babies at greater risk of death and serious harm.
-- Henci