Key message

• Intravenous (given through a vein) iron probably slightly reduces fatigue at 8 to 28 days compared with oral (by mouth) iron supplementation, but we are uncertain whether intravenous iron and oral iron supplementation compared with oral iron supplementation alone affect fatigue at 8 to 28 days.

• We are very uncertain about the effect of RBC transfusion versus IV iron on fatigue at 8 to 28 days, and there was no information on RBC transfusion versus no transfusion on fatigue at 8 to 28 days.

• The death of the mother was either not reported, or the evidence was very uncertain for any comparison. For oral iron compared with placebo (no treatment) or no treatment, there was no information on fatigue after 8 to 28 days.

What is iron deficiency anemia?

Anemia is a condition in which the blood contains less than normal hemoglobin (low blood level), which is shown in blood tests. Hemoglobin is the molecule in red blood cells that transports oxygen from the lungs to the tissues. Hemoglobin is a protein made up of peptides and iron. Inadequate iron intake, problems with iron absorption in the gut, or iron loss (bleeding) can cause iron deficiency anemia. Symptoms of anemia include fatigue, shortness of breath, dizziness and difficulty initiating breastfeeding. Women can bleed profusely during childbirth, and many pregnant women already have low iron stores or anemia, or both, which can worsen as a result of bleeding. Severe anemia has been linked to maternal death after delivery. Postpartum iron deficiency anemia is more likely to occur in low-income countries.

How is postpartum iron deficiency anemia treated?

Treatment for iron deficiency anemia includes oral iron supplements or intravenous iron. Studies have found a risk of serious allergic reactions with intravenous iron. Another option is to restore red blood cells by transfusion with blood from a blood donor.

What did we want to find out?

We wanted to know if one treatment was better than another in relieving anemia symptoms and if the treatment options were safe.

What did we do?

We searched medical databases for studies that looked at available treatments for women with postpartum anemia. We screened studies for credibility and included studies that we considered credible. The main outcomes were fatigue (fatigue) and death.

What did we find?

We included 33 studies with a total of 4558 women and performed seven treatment comparisons.

Eighteen trials (3026 women) compared intravenous iron with oral iron supplements. It is unclear whether intravenous iron affects the number of deaths. Only one woman died, and she had received intravenous iron. Based on two studies (515 women), we found that intravenous iron is likely to slightly reduce fatigue within 8 to 28 days compared with oral iron supplements. No studies investigated whether intravenous iron affects breastfeeding. Constipation was probably more common in women treated with oral iron supplements than in those receiving intravenous iron (10.7% vs < 1%). It is unclear whether intravenous iron has an effect on allergic reactions (anaphylaxis (severe allergic reaction) or hypersensitivity occurred in three women who received intravenous iron). Intravenous iron may increase hemoglobin levels, but important differences between studies prevented an estimate of the exact effect.

Two studies compared transfusions of red blood cells with intravenous iron. It is unclear whether transfusion of red blood cells affects the number of deaths, fatigue after 8 to 28 days, and breastfeeding. No studies have investigated whether intravenous iron affects constipation or allergic reactions. Transfusion of red blood cells may result in little or no difference in hemoglobin.

Three studies compared intravenous iron and oral iron supplementation with oral iron supplementation alone. No studies have looked at whether intravenous iron and oral iron supplements affect the number of deaths or breastfeeding. It is unclear whether intravenous iron and oral iron supplements affect allergic reactions or fatigue. Intravenous iron and oral iron supplementation may reduce constipation compared with oral iron alone (1 study; 128 women) and may result in little or no difference in hemoglobin levels after 8 to 28 days.

One study compared transfusions of red blood cells with no transfusions. No studies investigated whether red blood cell transfusions affect the number of deaths, fatigue, constipation, allergic reactions or hemoglobin levels. Transfusion of red blood cells may result in little or no difference in breastfeeding at six weeks postpartum (1 study; 297 women).

Three studies compared oral iron supplements with placebo. No studies examined whether oral iron supplementation affects the number of deaths, fatigue, breastfeeding, allergic reactions or hemoglobin levels within 8 to 28 days. Two studies did not report constipation for both groups.

What are the limitations of the evidence?

We have low to very low confidence in the evidence because the women in the studies knew what treatment they were receiving, which could have affected the results. In addition, few studies reported on outcomes important to patients. Only 8 of 33 included studies reported on fatigue.

How current is this evidence?

The certificate is valid until April 2024.