This is interesting, because it seems to validate all the experiences and opinions in this thread
LaLeche League's The Womanly Art of Breastfeeding p.282
Hypoglycemia in Newborns
"...Babies at greater risk for hypoglycemia include those who are premature or postmature, those who are small or large for gestational age, and those who have been deprived of oxygen. Hypoglycemia can also indicate infection or a metabolic disorder.
The most common cause of hypoglycemia is delayed or inadequate feedings. A baby who is put to the breast soon after birth and kept near the mother so he can nurse freely will be much less likely to show signs of hypoglycemia. In adults, treatment for low blood sugar includes small, frequent, high protein meals which is exactly what the newborn receives when he nurses often.
Giving glucose water feedings instead of nursing causes a sudden rise in the blood glucose levels and then a sudden drop. Glucose water feedings in the early days have also been associated with greater weight loss and higher bilirubin levels.
In some hospitals, glucose feedings are given to all babies whose birth weight falls above or below certain standards. It's a good idea to discuss this with your health care provider before the baby is born and request that routine glucose supplements not be given. If a blood test indicates a glucose supplement is necessary, artificial nipples can be avoided by giving the glucose by spoon, cup, or eyedropper. Sometimes the glucose is given by IV. Nursing at least ten to twelve times per day is the best way to stabilize a baby's glucose levels." (from the sixth revised edition)
I guess I lucked out with that nurse. She had me breastfeed Henry before she gave the supplement, with an eyedropper, and explained that he needed frequent nursing (of course I knew that already) and shouldn't need another supplement if he started nursing better (which he did). He did have a blood test that showed low blood sugar, it wasn't routine at all, and he did have inadequate feeding due to being doped up during the birth.
With my other two babies, one 10.5#, one 11.5#, there were no nursing problems in the first hour, and they never had blood sugar problems.