Iron deficiency and anaemia in the puerperium are associated with several important clinical consequences, most prominently physical fatigue. Current treatment practice with oral iron supplementation is associated with gastrointestinal side-effects and subsequent poor compliance. Red blood cell transfusion is also widely used to treat severe postpartum anaemia, though accumulating evidence questions its risk-benefit ratio. Intravenous iron has in previous studies been associated with fast improvement of haemoglobin and iron biochemical markers in the treatment of postpartum anaemia, but there is a lack of studies on patient reported outcomes.
 The thesis is based on three studies of intravenous iron (Monofer, iron isomaltoside) as an alternative to current treatment practice in postpartum iron deficiency and anaemia.
The first study is a randomised controlled trial comparing a high single-dose iron infusion with oral iron in women after postpartum haemorrhage without severe anaemia. The primary outcome was the aggregated change in physical fatigue within 12 weeks postpartum. We found a difference that was statistically significant, but less than the consensus-based and predefined minimal clinically relevant level. Across visits, particularly in the first weeks postpartum, we found statistically significant differences in fatigue and depression scores, all in favour of intravenous iron. We confirmed previous findings of a fast haematopoietic response and prompt replenishment of iron stores that persisted throughout the 12 weeks of follow-up. 
The second study, a randomised controlled pilot study, tested feasibility and exploratory outcomes of a high single-dose iron infusion compared with red blood cell transfusion for the treatment of severe postpartum anaemia. We found that randomisation could be feasible with some adjustments for a future study design. The difference in biochemical markers was larger than the patient-reported outcomes in the first week. A larger trial is needed to determine whether a high single-dose iron infusion is non-inferior to red blood cell transfusion in severe postpartum anaemia. 
The third study compared iron concentration in breast milk in a randomised sample of women receiving high single-dose iron infusion or oral iron. A high single-dose iron infusion lead to a transient increase in the iron concentration in breast milk, which remained within the normal range. 
In conclusion, iron isomaltoside seems to be associated with improved patient-reported outcomes compared to oral iron treatment, and in severe postpartum anaemia intravenous iron seems promising as an alternative to red blood cell transfusion.