Fifty percent of patients with HF have ID; either they have depleted iron stores (low ferritin (less than 100 ug/dL) and low transferrin saturation (equal to or less than 20%) or they have functional iron deficiency in the form of normal iron stores (ferritin (100–300 ug/dL) and low transferrin saturation (equal to or less than 20%) [8, 9]. Here, TF is linked to hydrops fetalis.