If 5 months pregnant w/ hemoglobin 9.0 and taking iron tablets and still very tired, should iron infusion be given?

May be. If your anemia is due to iron deficiency and is not responding to oral iron, intravenous infusion of iron would be a consideration. However, first the cause of anemia needs to be established. For now, increase the amount of iron you take and have your doctor check you out.