• Components sourced from donors with at least one previous transfusion in the last two years, and negative for all mandatory microbial investigations (to reduce risk of infection).
  • Components processed on day 0 (as opposed to those stored at ambient temperature for up to 24hr).
  • All components should be free of clinically-significant antibodies, including high-titre anti-A and anti-B (to reduce the risk of RBC haemolysis).
  • Group O (if not group O, then ABO compatible with both maternal and fetal blood group).
  • Negative for any antigens against which maternal alloantibodies are directed.
  • In citrate-phosphate-dextrose (CPD) additive solution (reduces the risk of toxicity from mannitol and adenine additives). 
  • Less than 5 days old (to reduce the risk of hyperkalaemia from haemolysed RBCs).
  • Irradiated (shelf-life 24hrs post-irradiation, to prevent transfusion-associated GVHD).
  • HbS negative (sickle screen negative).
  • K-negative (unless the maternal alloantibody is anti-k, in which case k-negative blood should be given)
  • Haematocrit 0.7-0.85 (to minimise the number of IUT procedures required).
  • CMV seronegative.
  • IAT crossmatch-compatible against maternal plasma
  • Approximate  volume 240ml, should not be transfused directly out of 4°C storage because of the risk of fetal bradycardia.