As explained in the previous question maternal hyperglycaemia leads to fetal hyperglycaemia, which in turn causes polyuria and thus causes polyhydramnios.Polyhydramnios leads to preterm delivery and not post datism. Excessive uterine enlargement because of polyhydramnios and macrosomia causes increased incidence of atonic PPH.Diabetes leads to increased incidence of congenital defects in fetus. Maternal hyperglycemia → to fetal hyperglycemia → hyperinsulinemia → to neonatal hypoglycemia at birth.