Parenteral iron therapy in obstetrics: 8 years experience with iron–sucrose complex

Abstract

Fe is an essential component of haem in myoglobin and accounts for 70 % of haemoglobin. The balance of Fe, unlike that of other metals such as Na or Ca, is regulated solely by gastrointestinal absorption, which itself depends on the bioavailability of Fe in food, i.e. the chemical Fe species. Factors that maintain Fe homeostasis by modulating Fe transfer through the intestinal mucosa are found at the luminal, mucosal and systemic levels. Fe deficiency and its consequence, Fe-deficiency anaemia, form the commonest nutritional pathology in pregnant women. The current gold standard to detect Fe deficiency remains the serum ferritin value. Previously there was general consensus against parenteral Fe administration, i.e. parenteral Fe was only recommended for special conditions such as unresponsiveness to oral Fe, intolerance to oral Fe, severe anaemia, lack of time for therapy etc. However, especially in hospital settings, clinicians regularly face these conditions but are still worried about reactions that were described using Fe preparations such as Fe–dextrans. A widely used and safe alternative is the Fe–sucrose complex, which has become of major interest to prevent functional Fe deficiency after use of recombinant erythropoietin Numerous reports show the effectiveness and safety of the Fe–sucrose complex. Good tolerance to this Fe formulation is partly due to the low allergenic effect of the sucrose complex, partly due to slow release of elementary Fe from the complex. Accumulation of Fe–sucrose in parenchyma of organs is low compared with Fe–dextrans or Fe–gluconate, while incorporation into the bone marrow for erythropoiesis is considerably faster. Oral Fe is only started if haemoglobin levels are below 110 g/l. If levels fall below 100 g/l or are below 100 g/l at time of diagnosis, parenteral Fe–sucrose is used primarily. In cases of severe anaemia (haemoglobin <90 g/l) or non-response to parenteral Fe after 2 weeks, recombinant erythropoietin is considered in combination. By using parenteral Fe–sucrose in cases of severe Fe deficiency, anaemia during pregnancy is treated efficiently and safely according to our results and rate of blood transfusion could be reduced considerably to below 1 % of patients per year.