JPAC Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee

9: EFFECTIVE transfusion in obstetric practice

Essentials

  • Inappropriate transfusions during pregnancy and the postpartum period expose the mother to the risk of haemolytic disease of the fetus and newborn (HDFN) in subsequent pregnancies.
  • Prevention and treatment of anaemia in pregnancy (most commonly due to iron deficiency) avoids unnecessary blood transfusion.
  • A blood count should be checked at the antenatal booking visit and at 28 weeks (allowing sufficient time to treat iron deficiency before delivery).
  • Oral iron replacement is appropriate for most patients, but intravenous iron (after the first trimester) may produce a more rapid response and should be used in women intolerant of oral iron.
  • Transfusion is rarely required in haemodynamically stable pregnant women with Hb >70 or 80 g/L unless there is active (or a high risk of) bleeding.
  • Cytomegalovirus (CMV) seronegative red cells should be provided for elective transfusions in pregnancy but standard, leucodepleted units may be used in an emergency to avoid delay.
  • Major obstetric haemorrhage remains an important cause of maternal death. Successful management depends on well-rehearsed multidisciplinary protocols, rapid access to red cells (including emergency group O negative units) and excellent communication with the transfusion laboratory. Access to cell salvage reduces use of donor blood and early administration of tranexamic acid may reduce mortality.
  • Pregnancies potentially affected by HDFN should be managed by specialist teams with facilities for early diagnosis, intrauterine transfusion and support of high-dependency neonates.
  • Alloimmunisation of RhD negative women is the most important cause of HDFN. It was a major cause of perinatal mortality before routine postnatal anti-D Ig prophylaxis was introduced.
  • Women may be alloimmunised by feto-maternal haemorrhage during pregnancy or at delivery, or by blood transfusion.
  • Anti-D Ig should be administered within 72 hours of delivery of a RhD positive baby or a potentially sensitising event in pregnancy in accordance with national guidelines.
  • The incidence of HDFN has been further reduced by the addition of routine antenatal anti-D prophylaxis (RAADP).