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

Overview

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 United Kingdom 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 United States, 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 United Kingdom. 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 United States 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.