Treatments for Iron-Deficiency Anaemia in Pregnancy

A Cochrane review [Abstract] 1 included 23 studies involving approximately 3 198 women. Oral iron in pregnancy showed a reduction in the incidence of anaemia (one trial, 125 women; relative risk 0.38; 95% Cl 0.26 to 0.55). Although iron treatments consistently increased maternal haematological indices in women diagnosed with iron-deficiency anaemia in pregnancy, no evidence was found that these laboratory improvements reflected in clinical improvements such as reduced preterm delivery, reduced infant low birthweight, lower rates of pre-eclampsia, sepsis or postpartum haemorrhage and its complications. Gastrointestinal adverse effects were more frequent with oral iron treatments, compared with other routes of iron administration. Compared with oral iron, intramuscular (IM) iron sorbitol and iron dextran improved haematological values, reduced the proportion of women with anaemia, and resulted in lower gastrointestinal side-effects, but these preparations were associated with higher rates of systemic reactions especially with IM iron. The findings also suggested that intravenous (IV) iron sucrose is effective, but there was uncertainty whether it increased the incidence of serious adverse effects such as thrombosis, which was frequent (9/41; 22%).

A meta-analysis 2 comparing intravenous and oral iron therapy included 15 studies with a total of 1938 participants. There was low quality evidence that intravenous iron was superior to oral iron in reducing the need for blood transfusion at delivery (Peto OR 0.19, [95% CI 0.05 to 0.78, 9 trials; number needed to treat was 95, 95% CI 81 to 348) and that intrvenous iron was superior to oral iron in increasing neonatal birthweight (mean difference 58 g; 95% CI 4 to 112 g; 8 trials).

Another meta-analysis 3 included 20 RCTs. Mean hemoglobin at delivery (WMD 0.66 g/dL, 95% CI 0.31 to 1.02 g/dL, 9 trials) was significantly higher after intravenous iron therapy. Intravenous iron was associated with higher birthweight (WMD 58.25 g, 95% CI 5.57 to 110.94 g, 8 trials) but no significant differences in blood transfusion, cesarean delivery, or neonatal hemoglobin.

References

• Reveiz L, Gyte GM, Cuervo LG et al. Treatments for iron-deficiency anaemia in pregnancy. Cochrane Database Syst Rev 2011;(10):CD003094. [PubMed]
• Qassim A, Grivell RM, Henry A et al. Intravenous or oral iron for treating iron deficiency anaemia during pregnancy: systematic review and meta-analysis. Med J Aust 2019;():. [PubMed]
• Lewkowitz AK, Gupta A, Simon L et al. Intravenous compared with oral iron for the treatment of iron-deficiency anemia in pregnancy: a systematic review and meta-analysis. J Perinatol 2019;39(4):519-532.[PubMed]