obgyn recommending Anatomy Scans for tracking GDM

I was wondering if it was normal for your obgyn to recommend anatomy scan appointments to track the baby's health during gestational diabetes? And if so how often do you have to go?

In our normal obgyn appointments, our doctor has an ultrasound machine but it's not as in depth as the perinatal appointment. The anatomy scan appointments are $130 with my insurance and I'm nowhere near hitting the deductible before my due date. I'm just worried, because if it's every 2 weeks, it will be $520 until the due date. Our last anatomy scan was at 28 weeks, and the baby was measuring normal and although I did love seeing our kid, it did feel very expensive for the appointment. We can afford it, but I was really looking forward to saving and spending the money on our baby after the birth.

Edit-- my bad I got the name wrong, it would be growth scans then I think billed at the same amount as anatomy scans

edit 2 - the perinatal doctor returned my call. Apparently we will just be going over the diabetes numbers and not doing scans. But I am pretty sure my insurance will still bill me at $130 for appointment for that. Am wondering why my obgyn can't help me with the number, will def ask him at the next appointment.