I believe the concern with diabetic moms is how well the baby can control his/her own blood sugar. Since that's a prime concern of a macrosomic baby *after birth*, maybe that's the reason for "considered to be"? In other words, we will treat this baby AS IF it is macrosomic, and monitor it's blood sugar for 24 hours. "Considered to be" is different than "is", after all.
My OB has something of this concern at my daughter's birth. I've got condition related to diabetes (insulin resistance) that I manage with diabetic medications. My OB is not very familiar with this condition, because it's not usually diagnosed until diabetes is fully developed. Fortunately, she's very good about listening to what I've learned about it, and researching what she doesn't know, so we get along well.
Anyway, at DD's birth, she wanted to follow the usual diabetic-mom protocol, which I believe is the same whether or not a baby is actually macrosomatic (DD was definitely not). The protocol involves blood sugar monitoring for 24 hours - it involves 11 heels sticks in that 24 hours. I didn't want to do it, because I knew my condition didn't put DD at risk for sugar issues at all. However, I agreed to her plan, simply to demonstrate to her what I already knew. Nothing like educating your doctor!
In the end, DD never had a single glucose reading out of line.
I do wonder about one aspect of this new policy, however. Why must the monitoring be done in the NICU? DD roomed in with me, and the nurses just came in to do the heel sticks according to their schedule. Maybe your doctor will write an order to that effect? I'm having a hard time imagining how/why the NICU director's policy would have more force than your doctor's orders.
Hey, here's a thought. Maybe you can get your insurance to say they won't pay for the NICU stay!