Daily vs. Intermittent Iron Therapy in Iron Deficient Pregnant Patients: A Randomized Noninferiority Trial

The Centers for Disease Control and Prevention estimates that as many as 8 million American women of childbearing age are iron deficient. In a typical singleton gestation, the maternal need for iron averages close to 1000 mg. Of this 300 mg is for the fetus and placenta; 500 mg for maternal hemoglobin mass expansion; and 200 mg that is normally shed through the gut, urine, and skin. The total amount of 1000 mg considerably exceeds the iron stores of most women and results in iron-deficiency anemia unless iron supplementation is given.

Correction of anemia and restitution of iron stores can be accomplished with simple iron compounds-ferrous sulfate, fumarate or gluconate. Oral iron is an effective treatment for iron deficiency anemia and is inexpensive, safe and widely available.

In the past, a standard approach to the treatment of iron deficiency anemia was oral ferrous sulfate 325 mg (65 mg elemental iron) spaced in 3 doses each day for a total daily dose of 195 mg elemental iron. However, recent absorption studies concluded that maximal absorption of iron occurs with a dose in the range of 40 to 80 mg of elemental iron daily. This study was done in non pregnant iron-deficient women. Greater doses do not result in more iron absorption and are associated with more side effects. The findings of this study have been implemented by many into various areas of medicine.

Daily oral supplementation in pregnant women has been a long-standing, cost-effective recommended intervention both in the public health and clinical fields. However, adherence to daily iron and folic acid supplementation still faces challenges. Data from national surveys from 46 countries (2003 to 2009) indicate that about 52% to 75% of mothers receive any iron tablets during pregnancy, and the duration of supplementation is usually short.

According to a study by Khalafallah, the side effects or oral iron therapy including gastrointestinal disturbances characterized by colicky pain, nausea, vomiting, diarrhea, and constipation occur in about 50% of a patient taking iron preparations, and the investigators estimate that their patients have similar complaints and intolerances.