How much bigger will my baby be if i have gdm?

Depends on control: A babies size with gdm will reflect the mothers average blood sugar status.Great control produces a baby no different than non-gdm mothers. Poor control(high blood sugars) translates to baby & baby organ overgrowth, higher risk of birth defects, need for baby to be on IV sugar after birth, etc.

It depends...: ... On how well you manage your sugars. Moms who follow the gdm diet and check their sugar regularly can have average sized babies. Work with your doctor and nutritionist to keep your sugars in a healthy range.