Gestational diabetes is a temporary (in most cases) form of diabetes in which the body does not produce adequate amounts of insulin to regulate sugar during pregnancy. It may also be called glucose intolerance or carbohydrate intolerance. Signs and symptoms can include:1  Sugar in urine (revealed in a test done in your doctor’s office). 2  Unusual thirst. 3  Frequent urination. 4  Fatigue. 5  Nausea. 6  Frequent vaginal, bladder, and skin infections. 7  Blurred vision.igns and symptoms can include: 1  Sugar in urine (revealed in a test done in your doctor’s office). 2  Unusual thirst. 3  Frequent urination. 4  Fatigue. 5  Nausea. 6  Frequent vaginal, bladder, and skin infections.