I wonder if the mother has diabetes? The article commented on the baby's blood sugar, but not the mother. When I worked in hospitals, I was aware of diabetic mothers having large (e.g., 11 pound) babies. Frequently, a C-section or an early induction was necessary, because the baby was too big for the mother to deliver.
I didn't see anything about the mother's sugar either............but I have a cousin on my husbands side who had an 11 pounder without diabetes as well as one of my aunts, I guess we just grow 'em big too, but dang! And they were both born natural and neither was a particularly large framed person.