@SailorJerry - Opinion is divided on the one hour glucose test, as it's also called. A lot of people in the natural childbirth and midwifery communities think that it's not necessary. A woman with gestational diabetes will indeed usually have other symptoms. She might feel unwell or have sugar spilling into her urine (one reason they have pregnant woman pee in a cup so often).
Most OBs, however, do them routinely for all pregnant women. But when I told my OB that I wasn't comfortable doing the syrup test, he didn't force the issue. He did suggest that I do a fasting glucose test as an alternative, so I went to the lab one morning right when it opened and had some blood drawn. The lab tech was a little confused because it didn't say that it was a "post dose" blood draw!