Thanks for your kind wishes melbel!

abs, I'm not sure why you've concluded that Henci Goer is advocating for "no treatment". Look at the last paragraph:

Still, midwives can winnow some grain from the chaff. Maternal weight has the strongest correlation with macrosomia rate; it makes sense to advise heavily overweight women to lose weight before becoming pregnant. Pregnancy makes extra demands on insulin production; to minimize the pressure, pregnant women should eat a diet low in simple sugars, high in complex carbohydrates and fiber, and moderate in fat. Moderate, regular exercise also improves glucose tolerance. Within the GD population lurk a few women who were either undiagnosed pregestational diabetics or who were tipped into true diabetes by the metabolic stress of pregnancy; a fasting glucose to screen for them might be prudent. And, of course, midwives already use strategies that help women minimize the likelihood of operative delivery or birth injury. Finally, to reduce the chance of neonatal hypoglycemia, the baby should be put to breast soon after the birth, especially if the baby is big, small, or the labor has been difficult.
You mention thresholds for treatment. It would be worth treating 10,000 women in order to help 1 woman if there were absolutely no negative outcomes from treatment - but this is never the case with any kind of drug/procedure/treatment. The benefits to that 1 woman have to be weighed against the potential for harm to the other 9,999.