INS and diabetes mellitus: Although, mean fasting plasma glucose did not differ significantly between groups during the second and third trimester of pregnancy and in the regression model, mean fasting plasma glucose during the first trimester was not significantly associated with a villous changes consistent with FTOD (OR 0.963, 95% CI 0.919–1.009, p = 0.111), the possibility that beneficial effect of insulin therapy in terms of placental vascular circulation is linked to a better diabetes control cannot be excluded.