Is oral or IV iron therapy more beneficial for postpartum anemia?
IV iron is the better choice for a select group of women. In a systematic review that evaluated more than 1,000 women who received oral iron versus 1,000 women who received intravenous (IV) iron for postpartum anemia (defined as hemoglobin level less than 12 g/dL), IV iron preparations were more effective in raising hemoglobin levels (almost 1 g/dL higher) at 6 weeks postpartum and were better tolerated than oral iron.
The systematic review included studies, however, that excluded women treated for antepartum anemia, a group that may benefit from aggressive correction of iron deficiency. Another study weakness is that all the oral iron regimens used were dosed either daily or multiple times per day, which may lead to difficulty with adherence and can decrease overall iron absorption compared with an every-other-day regimen.3
Future studies are needed to determine 1) which women with what level of anemia will benefit the most from postpartum IV iron and 2) the hemoglobin level at which IV iron is a cost-effective therapy.
Given the efficacy and reduced adverse effects associated with IV iron therapy demonstrated in the systematic review by Sultan and colleagues, I recommend treatment with IV iron for women with moderate to severe postpartum anemia (defined in pregnancy as a hemoglobin level less than 10 g/dL and ferritin less than 40 µg/L) who have not received blood products or for women who are unable to tolerate or absorb oral iron (such as those with a history of bariatric surgery, gastritis, or inflammatory bowel disease). In our institution, we frequently give IV iron sucrose 300 mg prior to discharge due to ease of administration. For women with mild iron deficiency anemia (hemoglobin greater than 10 g/dL), I prescribe every-other-day oral iron in the form of ferrous sulfate 325 mg, which effectively raises the hemoglobin level and limits the gastrointestinal side effects associated with more frequent dosing.
Julianna Schantz-Dunn, MD, MPH
