The main advantage of intravenous ferric carboxymaltose administration is to increase the Hb before delivery, particularly among patients who did not respond, were unable to tolerate, or were noncompliant with oral iron supplementation. This may potentially decrease the rate of postnatal transfusion in patients with iron deficiency anemia who experienced further blood loss during delivery. This evidence concerns the gene GSTM1 and Iron deficiency anemia.