GDM: usually around 24-28 wk GA, anti-insulin factors produced by placenta and high maternal cortisol levels create increased peripheral insulin resistance → higher fasting glucose → leading to GDM and/or exacerbating pre-existing DM
Macrosomia pathogenesis - Hyperglycemia in fetus → ↑ insulin & growth factors/hormone → fetal growth and deposition of fat and glycogen.