Results of the First American Prospective Study of Intravenous Iron in Oral Iron-Intolerant Iron-Deficient Gravidas

Am J Med. 2017 Dec;130(12):1402-1407. doi: 10.1016/j.amjmed.2017.06.025. Epub 2017 Jul 21.


Background: Anemia affects up to 42% of gravidas. Neonatal iron deficiency is associated with low birth weight, delayed growth and development, and increased cognitive and behavioral abnormalities. While oral iron is convenient, up to 70% report significant gastrointestinal toxicity. Intravenous iron formulations allowing replacement in one visit with favorable side-effect profiles decrease rates of anemia with improved hemoglobin responses and maternal fetal outcomes.

Methods: Seventy-four oral iron-intolerant, second- and third-trimester iron-deficient gravidas were questioned for oral iron intolerance and treated with intravenous iron. All received 1000 mg of low-molecular-weight iron dextran in 250 mL normal saline. Fifteen minutes after a test dose, the remainder was infused over the balance of 1 hour. Subjects were called at 1, 2, and 7 days to assess delayed reactions. Four weeks postinfusion or postpartum, hemoglobin levels and iron parameters were measured. Paired t test was used for hemoglobin and iron; 58/73 women were questioned about interval growth and development of their babies.

Results: Seventy-three of 74 enrolled subjects completed treatment. Sixty had paired pre- and posttreatment data. The mean pre- and posthemoglobin concentrations were 9.7 and 10.8 g/dL (P < .00001), transferrin saturations 11.7% and 22.6% (P = .0003), and ferritins 14.5 and 126.3 ng/mL, respectively (P < .000001). Six experienced minor infusion reactions. All resolved. Data for 58 infants were available; one was low on its growth charts for 11 months. The remaining 57 were normal. None were diagnosed with iron deficiency anemia.

Conclusion: Intravenous iron has less toxicity and is more effective, supporting moving it closer to frontline therapy.

Keywords: Intravenous iron; Iron deficiency anemia; Pregnancy.

MeSH terms

  • Administration, Intravenous
  • Administration, Oral
  • Female
  • Humans
  • Iron Compounds / administration & dosage*
  • Iron Compounds / adverse effects
  • Iron Deficiencies*
  • Pregnancy
  • Pregnancy Complications / drug therapy*
  • Prospective Studies


  • Iron Compounds