A prospective randomised controlled trial of a single intravenous infusion of ferric carboxymaltose vs single intravenous iron polymaltose or daily oral ferrous sulphate in the treatment of iron deficiency anaemia in pregnancy

Iron deficiency anaemia (IDA) is the most common nutritional deficiency affecting pregnant women worldwide. This study aims to compare the efficacy and safety of a newly available intravenous (IV) iron preparation, ferric carboxymaltose (FCM), against IV iron polymaltose (IPM), and standard oral iron (ferrous sulphate) for the treatment of IDA in pregnancy. This is an open-labelled prospective randomised controlled trial (RCT) with intention-to-treat analysis conducted at a primary health care facility with a single tertiary referral centre in Launceston. Tasmania, Australia. A 3-arm randomised controlled trial was conducted comparing a single IV infusion of 1000 mg of FCM (n = 83 patients) over 15 minutes against a single IV infusion of 1000 mg of IPM (n = 82) over 2 hours against 325 mg daily oral ferrous sulphate (n = 81) until delivery, for the treatment of IDA in pregnancy. A total of 246 consecutive pregnant women were recruited between September 2013 and July 2014. The median age was 28 years, with a median and mean gestation of 27 weeks. The median serum ferritin was 9 µg/L, with a mean of 13 µg/L. The mean haemoglobin (Hb) was 114 g/L. The primary outcome was the change in ferritin and Hb levels at 4 weeks after intervention. Secondary outcomes included ferritin and Hb improvements at predelivery, safety, tolerability, quality of life (QoL), cost utility, and fetal outcomes. The mean Hb level differences between the baseline intervention time point and 4 weeks thereafter were significantly higher in the FCM versus the oral group by 4.35 g/L (95% CI: 1.64-7.05; P = 0.0006) and in the IPM vs the oral group by 4.08 g/L (95% CI: 1.57-6.60; P = 0.0005), but not different between the FCM and IPM groups (0.26 g/L; 95% CI: 2.59 to 3.11; P = 0.9740). The mean ferritin level differences were significantly higher at 4 weeks in the FCM vs oral iron group by 166 µg/L (95% CI: 138-194; P < 0.0001) and in the IPM vs oral iron group by 145 µg/L (95% CI: 109-1180, P < 0.0001), but not between the 2 IV groups (21.5 µg/L; 95% CI: 23.9 to 66.9; P = 0.4989). Administration of IV FCM during pregnancy was safe and better tolerated than IV IPM or oral iron. Compliance to oral iron was the lowest amongst treatment groups with one-third of the patients missing doses of daily iron tablets. Significant improvement in overall QoL scores was observed in both IV iron supplement groups by achieving normal ferritin following effective and prompt repletion of iron stores, compared to the oral iron group (P = 0.04, 95% CI: 21.3, 1.8). The overall cost utility of IV FCM and IV IPM appear to be similar to oral iron. There were no differences in the fetal outcomes between the 3 trial arms.

In conclusion, this study demonstrates that a single IV iron infusion is an effective and safe option for treatment of IDA during pregnancy. FCM was more convenient than other treatments. Rapid parenteral iron repletion can improve iron stores, Hb levels and QoL in pregnant women, with ongoing benefits until delivery. Integration of IV iron for IDA in pregnancy can potentially improve pregnancy outcomes for the mother. Update of guidelines to integrate the use of new IV iron preparations in pregnancy is warranted.