Intravenous Ferric Carboxymaltose Versus Intravenous Iron Sucrose in Pregnancy and Postpartum

Introduction

Iron deficiency anemia during pregnancy and postpartum is one of the most common nutritional deficiencies in the world. Women with iron deficiency anemia have a higher risk of disease occurrence for both mother and fetus. Therefore, iron deficiency anemia should be adequately managed among pregnant patients to prevent maternal conditions like depression, lactation failure, headaches, and tiredness. In addition, conditions like fetal growth restriction, infection, preterm birth, and intrauterine fetal death can happen to infants and fetuses. For the treatment of iron deficiency anemia among pregnant patients, the most frequently used intravenous (IV) formulations are ferric carboxymaltose and iron sucrose.

What Is Iron Deficiency Anemia, and How Does It Affect Pregnancy and Postpartum?

• Iron deficiency anemia is when the body produces inadequate amounts of iron in the blood.

• The body needs a mineral called iron to produce red blood cells.

• Red blood cells are cells found in the blood. It contains a protein called hemoglobin.

• An iron deficiency depresses the erythropoietic system, affecting the production of red blood cells and resulting in a reduced hemoglobin level.

• Iron is responsible for blood, red blood cells, and hemoglobin formation. An iron deficiency disrupts the whole process.

• When the physiologic balance of iron production and its utilization is disturbed, iron depletion occurs, and the final state of iron depletion is called iron deficiency anemia.

• The body would not be healthy if the red blood cells are not produced enough and can start developing other conditions or diseases.

• Iron demand in pregnancy increases as iron is required to develop the placenta and the fetus and support the mother's increased blood volume.

• Pregnant women also undergo blood loss during and after delivery, leading to an iron deficiency during the postpartum period.

• Pregnant women with an iron deficiency might require blood transfusions. They can have reduced immune function, reduced cognitive and physical performance, cardiovascular problems, increased tiredness, and chances of depressive episodes.

What Is Intravenous Ferric Carboxymaltose?

Ferric carboxymaltose (FCM) is an iron replacement product given intravenously for managing iron deficiency anemia in patients who cannot take iron supplements or for whom the iron supplements do not work efficiently.

What Role Does Intravenous Ferric Carboxymaltose Play in Pregnancy and Postpartum?

• A progression from small amounts of iron deficiency to iron deficiency anemia is common as increased demand for iron happens during pregnancy. This is because more iron is required to support the maternal blood volume, the growing fetus, and the placenta.

• The demand increases further in the postpartum period because of the blood loss with delivery.

• Intravenous iron supplementation is given for moderate to severe anemia. It is also given in cases where there is an intolerance of oral iron and when the oral iron supplements are not absorbed efficiently.

What Is Intravenous Iron Sucrose?

Iron sucrose (IS) is an intravenous replacement for iron deficiency anemia. The doctor usually determines the dosing and amount of iron sucrose based on the patient's hemoglobin levels and other iron-related parameters and also the patient's response to the medication. It works by replenishing the depleted iron stores in the body for them to produce more red blood cells.

What Role Does Intravenous Iron Sucrose Play in Pregnancy and Postpartum?

• Iron sucrose is one of the first manufactured intravenous iron preparations.

• Iron sucrose corrects iron deficiency by promoting erythropoiesis (red blood cell production) and reducing the required doses of erythropoiesis-stimulating agents.

• Iron sucrose is effective, well tolerated, and increases the bioavailability of iron supplies in the body.

• Iron sucrose, when administered to pregnant women from their third trimester until delivery, significantly increased the hemoglobin levels, thereby reducing the need for blood transfusion.

• Iron sucrose has shown greater efficacy than oral iron administration for women with iron deficiency anemia during their postpartum period.

What Are the Differences Between Intravenous Ferric Carboxymaltose and Intravenous Iron Sucrose in Pregnancy and Postpartum?

• Previously, iron dextran formulations were used, which caused side effects like anaphylaxis. Iron sucrose and ferric carboxymaltose are the dextran-free intravenous alternatives for iron and have very few incidences of anaphylaxis.

• Intravenous ferric carboxymaltose and intravenous iron sucrose restore iron stores and correct the hemoglobin deficiency in the blood. However, the increase in hemoglobin levels was noted more in patients who underwent FMC therapy than in IS therapy.

• The serum ferritin levels were increased during both the IV treatments but were noted more in patients who underwent FMC therapy. Ferritin is a blood protein that stores iron in the body's cells. The levels of serum ferritin mainly determine the iron stores in the body.

• Even though iron sucrose does not cause any serious adverse effects, it has minor side effects, which are caused due to its high pH and high osmolarity. Ferric carboxymaltose has a neutral pH, osmolarity, and increased bioavailability. These pH and osmolarity differences make ferric carboxymaltose a better alternative than iron sucrose.

• In pregnant women who need correction for anemia and iron deficiency, rapid delivery of a large dose of ferric carboxymaltose (1000 mg) as a single infusion caused a significant effect than the low dosage limits of iron sucrose (200 mg). Iron sucrose also has a prolonged infusion time and requires multiple infusions making it less favorable than FCM.

• FCM causes rapid iron replacement and benefits pregnant women at risk for postpartum hemorrhage and patients who require surgery for uncontrolled menorrhagia (abnormally heavy bleeding).

• FCM has higher efficacy and can be tolerated well in patients with chronic heart failure and irritable bowel disease.

• Regarding patient comfort, convenience, risk profile, efficacy, and institutional resource utilization, ferric carboxymaltose is better than iron sucrose. This is due to its patient-friendly dosing, immediate effect on iron levels, and fewer hospital visits for FCM therapy.

• Both these IV formulations have side effects like nausea, vomiting, headache, chest tightness, hot flashes, mild fever, and arthralgia (joint pain) due to the toxic reaction of free iron in the IV formulations.

• However, this incidence is lower in FCM because the carboxymaltose shell of the ferric carboxymaltose reduces the release of free iron, which results in more amounts of iron into the tissues.

Conclusion

Appropriate management of iron deficiency can help pregnant women restore their iron stores during pregnancy and keep the mother and the baby healthy. The treatment of iron deficiency anemia includes intravenous ferric carboxymaltose and iron sucrose formulations. However, in pregnancy and postpartum, intravenous ferric carboxymaltose therapy is found to be more effective than intravenous iron sucrose due to its rapid iron replacement with a single infusion.