Intravenous Iron for Iron-deficiency Anemia in Pregnancy: a Randomized Controlled Trial (IVIDA)

Iron deficiency is the most common cause of anemia in pregnancy worldwide, and, when severe, can have serious consequences for mothers and babies. While treatment of iron-deficiency anemia with iron supplementation is recommended, treatment strategies remain controversial: the American College of Obstetrics and Gynecology recommends oral iron supplementation with parental iron reserved for the rare patient who cannot tolerate or will not take oral iron, while UK professional organizations recommend a more liberal use of parenteral iron. The reason for these disparate recommendations is that few high-quality studies comparing oral to parenteral iron have been conducted in developed countries, and the potential impact of parental iron treatment on obstetric and perinatal outcomes remains unclear. We propose the first randomized-controlled trial in the United States describing the effectiveness and safety of treating pregnant women with iron-deficiency anemia with a protocol including parenteral iron compared with a protocol based on oral iron.

Iron deficiency is the most common cause of anemia in pregnancy worldwide, and, when severe, can have serious consequences for mothers and babies. In the U.S., anemia affects nearly 20% of pregnancies and the majority is iron-deficiency anemia. Therefore, treatment of iron-deficiency anemia with iron supplementation is recommended.1 However, there is controversy about the treatment strategies. The American College of Obstetrics and Gynecology recommends oral iron supplementation for iron-deficiency anemia in pregnancy, with parental iron reserved only for the "rare patient who cannot tolerate or will not take oral iron" (1) Conversely, guidelines from the U.K. are more liberal on the use of parental iron for the treatment of iron-deficiency anemia in pregnancy (2). Both treatment guidelines are based on limited data regarding the risks and benefits of parental iron for treatment of iron-deficiency anemia in pregnancy. The majority of randomized trials were conducted in developing country settings. In fact, few high-quality studies have been conducted in developed countries, and none has been conducted in the U.S. Moreover, there is limited data from prior studies on the impact of parental iron treatment on perinatal outcomes. The most recent Cochrane review including mostly from trials conducted in low-income countries found that, although parenteral iron improved hemoglobin levels and iron stores than the oral route, no clinical outcomes were assessed and there were insufficient data on adverse effects (3). The authors concluded that "large, good quality trials, assessing clinical outcomes including adverse effects … are required" (3). This randomized controlled trial aims to assess the effectiveness and safety of treating pregnant women with iron-deficiency anemia with a protocol including parenteral iron compared with a protocol based on oral iron. We hypothesize that treating iron-deficiency anemia with parental iron is associated with improved maternal and neonatal outcomes compared with a protocol based on oral iron. To increase generalizability of the findings, we will use broad inclusion criteria and analyze data using the intention-to-treat principle.

Iron Deficiency Anemia of Pregnancy, oral iron supplementation, parenteral iron supplementation, maternal anemia

All participants at less than 28 weeks gestation will have an anemia evaluation and work up per standard prenatal care. Those who meet a clinical diagnosis of iron-deficiency anemia will initiate oral iron and have their CBC rechecked between 24 and 28 weeks gestation. If their hemoglobin is less than 10 mg/dL, they will be randomized to either continue their oral iron supplementation or receive a single intravenous dextran iron transfusion. If the patient is enrolled after 28 weeks and receives a diagnosis of iron deficiency anemia, she will be randomized at that time.

The research team will be blinded to the patients' treatment arm. A team of resident physicians who are unfamiliar with the study aims will provide standard obstetric care to all participants.

Women randomized to receive intravenous iron infusion will receive a single infusion of dextran 1000mg IV as an inpatient on the antepartum or Labor & Delivery Unit. They will receive continuous fetal monitoring for 30 minutes before and after the infusion as well for the duration of the infusion

Women randomized to continue oral iron will continue to take ferrous sulfate 325mg one to three tablets daily, with the final dose at the discretion of the patient's obstetric provider.

Research assistants will contact all patients receiving iron infusions 2 days after their infusion to assess for symptoms via a telephone questionnaire.

Participant receiving transfusion of packed red blood cells during admission for delivery of infant obtained via medical chart review.

APGAR scores. The APGAR score measures the physical condition of a newborn infant on a scale from 0 to 10 by adding points (2, 1, or 0) for heart rate, respiratory effort, muscle tone, response to stimulation, and skin color.

Neonatal morbidity composite, defined by the occurrence of one or more of the following neonatal morbidities: neonatal seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, neonatal hypothermic therapy, sepsis, respiratory distress syndrome, hyperbilirubinemia requiring photo therapy, birth injury, or meconium aspiration syndrome, NICU admission

Inclusion Criteria: Iron-deficiency anemia (serum ferritin <30 micrograms, normal hemoglobin electrophoresis, and hemoglobin <10 mg/dL), planned delivery at Barnes-Jewish Hospital Exclusion Criteria: Non-iron-deficiency anemia, multiple gestation, prenatally diagnosed major fetal anomalies, known aneuploidy, planned delivery at other hospital, inability to obtain consent

American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 95: anemia in pregnancy. Obstet Gynecol. 2008 Jul;112(1):201-7. doi: 10.1097/AOG.0b013e3181809c0d. Erratum In: Obstet Gynecol. 2020 Jan;135(1):222.

Pavord S, Myers B, Robinson S, Allard S, Strong J, Oppenheimer C; British Committee for Standards in Haematology. UK guidelines on the management of iron deficiency in pregnancy. Br J Haematol. 2012 Mar;156(5):588-600. doi: 10.1111/j.1365-2141.2011.09012.x. Erratum In: Br J Haematol. 2012 Aug;158(4):559.

Reveiz L, Gyte GM, Cuervo LG, Casasbuenas A. Treatments for iron-deficiency anaemia in pregnancy. Cochrane Database Syst Rev. 2011 Oct 5;(10):CD003094. doi: 10.1002/14651858.CD003094.pub3.

Lewkowitz AK, Stout MJ, Cooke E, Deoni SC, D'Sa V, Rouse DJ, Carter EB, Tuuli MG. Intravenous versus Oral Iron for Iron-Deficiency Anemia in Pregnancy (IVIDA): A Randomized Controlled Trial. Am J Perinatol. 2022 Jun;39(8):808-815. doi: 10.1055/s-0041-1740003. Epub 2021 Nov 28.