markdownabstract__Abstract__ This thesis describes studies into red blood cell (RBC) transfusion policy in obstetrics. The WOMB trial is a non-inferiority trial that included women with acute anaemia after postpartum haemorrhage (PPH) (Hb concentration 4.8 to 7.9 g/dL), without severe anaemic complaints, to either RBC transfusion or non-intervention. Primary outcome was physical fatigue, measured by the Multidimensional Fatigue Inventory, at day three postpartum. Results demonstrate that RBC transfusion mildly improved physical fatigue. Non-inferiority of a non-intervention policy could not be proven. However, the difference in physical fatigue was small and clinical significance of the difference is doubtful. Complication rate and length of hospital stay were comparable between study arms though women allocated to non-intervention, had a 10-15% chance of receiving an escape transfusion. A prediction model on the need for escape RBC transfusion in women that were initially treated with a non-intervention policy identified several clinical variables (primiparity, multiple pregnancy, total blood loss during delivery and Hb concentration) predicting the need for escape RBC transfusion. Addition of health-related quality of life-scores improved this prediction model. After external validation, the model and its formula (to calculate an individual’s probability of needing an escape RBC transfusion after non-intervention) may be an important tool for counselling and decision making.