* kliehauer Betke test is the procedure of choice to assess the volume of the fetal maternal bleeding * It should be done as soon as possible (within 2hours) after delivery in women with suspected large feto maternal haemorrhage who need larger amounts of anti D * This method is based on the fact that an acid solution elutes the adult but not the fetal hemoglobin from the red cells. * Fetal erythrocytes appear in a smear stained dark red and surrounded by colourless ghosts that are adult erythrocytes without hemoglobin. * This test can detect as little as 0.2ml of fetal blood diluted in 5litres of maternal blood. * Following clinical scenarios are associated with large feto maternal bleeding: 1. Traumatic deliveries including cesarean 2. Manual removal of placenta 3. Still bihs and intrauterine deaths 4. Abdominal trauma during the third trimester 4. Twin pregnancies at delivery 5. unexplained hydrops fetalis Reference: Greentop guidelines no: 22