What evidence exists to support post-partum IV iron replacement while hospitalized? Is there value to providing full replacement in hospital rather than delaying to outpatient? What IV iron formulation and dose is best supported in this setting?

Comment by InpharmD Researcher

Guidance from ACOG recommends considering IV iron in postpartum women who cannot tolerate or do not respond to oral iron or in women who had severe iron deficiency later in pregnancy. No dosing recommendations were made, but studies used ferrous sucrose doses up to 600 mg, ferric carboxymaltose doses up or 3,000 mg, or iron dextran 1,000 mg with various numbers of infusions across different time periods. Among available products, iron sucrose has been most commonly studied in postpartum anemia but typically requires multiple infusions, whereas ferric carboxymaltose allows larger doses to be administered in fewer infusions. While there is an overall lack of data to determine whether full replacement during hospitalization is preferred over outpatient supplementation, prompt iron therapy is recommended to reduce anemia-related comorbidities and may improve maternal physical and mental well-being during the postpartum period due to more rapid hemoglobin recovery compared with oral iron.

A literature search was conducted using PubMed and Google Scholar to identify studies evaluating intravenous iron therapy for postpartum anemia, including comparisons with oral iron and blood transfusion. Relevant systematic reviews, clinical trials, and guideline recommendations were reviewed.

Background

Per 2021 American College of Obstetricians and Gynecologists (ACOG) guidelines, both oral and parenteral iron are effective for repletion of iron stores in postpartum women. Meta-analyses have found intravenous (IV) iron resulted in higher hemoglobin concentrations 6 weeks postpartum compared to oral iron replacement (mean difference 0.9 g/dL; 95% CI 0.4 to 1.3 g/dL; p= 0.0003). Additionally, there are fewer gastrointestinal adverse effects associated with IV iron compared with oral iron. Based on the available evidence, ACOG recommends considering parenteral iron for pregnant (after the first trimester) or postpartum women who cannot tolerate or do not respond to oral iron. Parenteral iron can also be considered for women with severe iron deficiency later in pregnancy. [1]

A 2024 review highlights the significant burden of PPA, primarily caused by iron deficiency (ID) and exacerbated by peripartum blood loss. The review elucidates the effectiveness of timely detection and iron supplementation therapy in improving maternal health outcomes post-delivery. Despite the existence of international guidelines recommending screening for anemia and iron supplementation when necessary, the implementation of PPA management remains inconsistent. Recent findings reinforce that IV iron is superior to oral iron in rapidly replenishing iron stores and improving both physical and mental health in postpartum women. Clinical data indicate that maternal quality of life benefits significantly from IV iron administration due to quicker restoration of Hb levels and alleviation of anemia-associated symptoms. Consequently, the review advocates that addressing ID during pregnancy is crucial in preventing PPA, suggesting that broadened awareness and adherence to existing anemia management guidelines could substantially impact maternal well-being and postpartum recovery. [2]

A 2019 systematic review and meta-analysis (N= 15) compared oral versus IV iron therapy to treat postpartum anemia. IV iron formulations utilized within the studies included ferrous sucrose (9/15 studies; total dose ranged from 300 to 600 mg), ferric carboxymaltose (4/15 studies; total dose ranged from 1,000 to 3,000 mg), iron maltoside, and iron dextran (one study; total dose 1,000 mg). Higher postpartum week 6 hemoglobin concentrations were observed in the IV iron group compared to the oral iron group as described above. Additionally, women receiving IV iron showed higher hemoglobin concentrations at postpartum weeks 1, 2, and 3 along with increased ferritin concentrations at postpartum weeks 1, 2, 4, and 6. Side effects reported with use of IV iron included flushing, nausea, headache, infection, constipation, muscle cramps, headache, increase in alanine transferase (ALT), rash, and urticaria. When IV iron side effects were compared to oral iron side effects, a statistically significant greater rate of occurrence with IV treatment was only reported for flushing (p= 0.01). For other side effects reported to have statistically significant differences between oral and IV (i.e., constipation and dyspepsia), the risk was greater with oral iron. Overall, there was a lower risk of gastrointestinal side effects with IV iron. The findings suggest that among women with postpartum anemia, hemoglobin concentrations at 6 weeks postpartum were almost 1 g/dL higher in women who received IV iron compared to oral iron. The safety profile of IV iron was also reassuring. Given the weaker hemoglobin response and higher risk of gastrointestinal side effects with oral iron use, it is suggested that IV iron be considered as a viable treatment option for postpartum iron deficiency anemia. [3], [4]

A 2022 prospective, quasi-randomized trial evaluated the use of IV iron sucrose versus blood transfusion in 44 hemodynamically stable postpartum women with moderate anemia (Hb 7-8 g/dL). Women in rural Bangladesh received either iron sucrose 600 mg IV (200 mg as a single dose repeated 3 times) or 2 units of blood transfusion (in 2 days) 48 h after delivery based on time of study enrollment. After 6 weeks, the mean hemoglobin level increased by 4.2 g/dL in the iron sucrose group and 4.5 g/dL in the transfusion group. Serum ferritin increased by 40.5 mcg/L with iron sucrose compared to 44.8 mcg/L with transfusion. No significant differences were observed in terms of any hematological parameters. The authors concluded that IV iron sucrose is as effective as blood transfusion in replenishing the hemoglobin and iron storage status in hemodynamically stable women with moderate postpartum anemia. [5]

References: [1] American College of Obstetricians and Gynecologists' Committee on Practice Bulletins—Obstetrics. Anemia in Pregnancy: ACOG Practice Bulletin, Number 233. Obstet Gynecol. 2021;138(2):e55-e64. doi:10.1097/AOG.0000000000004477
[2] Neef V, Choorapoikayil S, Hof L, Meybohm P, Zacharowski K. Current concepts in postpartum anemia management. Curr Opin Anaesthesiol. 2024;37(3):234-238. doi:10.1097/ACO.0000000000001338
[3] Sultan P, Bampoe S, Shah R, et al. Oral vs intravenous iron therapy for postpartum anemia: a systematic review and meta-analysis. Am J Obstet Gynecol. 2019;221(1):19-29.e3. doi:10.1016/j.ajog.2018.12.016
[4] Nash CM, Allen VM. The Use of Parenteral Iron Therapy for the Treatment of Postpartum Anemia. J Obstet Gynaecol Can. 2015;37(5):439-442. doi:10.1016/S1701-2163(15)30259-0
[5] Hye RA, Sayeeda N, Islam GMR, Mitu JF, Zaman MS. Intravenous iron sucrose vs. blood transfusion in the management of moderate postpartum iron deficiency anemia: A non-randomized quasi-experimental study. Heliyon. 2022;8(2):e08980. Published 2022 Feb 17. doi:10.1016/j.heliyon.2022.e08980