Iron Infusion at 37 Weeks Gestation for Iron Deficiency Anemia

Clinical Context at 37 Weeks

At 37 weeks gestation, intravenous iron infusion is the preferred treatment over oral iron due to the advanced gestational age and limited time for oral supplementation to be effective, with oral iron typically requiring 4 weeks to demonstrate adequate response, which may extend beyond delivery, and the prevalence of iron deficiency increasing significantly in the third trimester, affecting up to 29.5% of pregnant women 1

The American College of Obstetricians and Gynecologists (ACOG) recommends screening all pregnant women and treating iron deficiency anemia with supplemental iron 2
The Centers for Disease Control and Prevention (CDC) recommends screening and low-dose iron supplementation for all pregnant women 3, 2

Confirm iron deficiency anemia before treatment with hemoglobin/hematocrit appropriate for gestational age plus low ferritin (<30 μg/L), and remember that physiologic anemia of pregnancy (hemodilution) is normal and should not be confused with true iron deficiency anemia, and serum ferritin is an acute phase reactant and may be falsely elevated during inflammation, potentially masking iron deficiency 1
In women of African, Mediterranean, or Southeast Asian ancestry, mild anemia unresponsive to iron may indicate thalassemia minor or sickle cell trait 1