HDFN Detection and Treatment PDF

Haemolytic Disease of the fetus and Newborn - Detection and Treatment BMS5203 BLOOD & CELULAR SCIENCES Diagnostic testing – Laboratory Based  All pregnant women ABO and RhD grouped and screened for the presence of red cell antibodies during early (Booking sample) and late pregnancy (28 week...

Haemolytic Disease of the fetus and Newborn - Detection and Treatment BMS5203 BLOOD & CELULAR SCIENCES Diagnostic testing – Laboratory Based  All pregnant women ABO and RhD grouped and screened for the presence of red cell antibodies during early (Booking sample) and late pregnancy (28 weeks gestation).  When present, antibody specificity is identified and when an antibody poses a risk of HDFN , the levels are determined and monitored to identify sudden changes which would indicate problems for the fetus.  Monitor antibody levels by antibody quantitation ( anti-D, -c) and antibody titration for all other antibodies.  Paternal sampling – phenotype and zygosity testing when appropriate (Rhc, RhD, K) Alternative Methods  Foetal blood type  Chorionic villus sampling  Cell free fetal DNA (cffDNA) from maternal blood sample  Amniotic fluid sampling for rising bilirubin levels – why?  Ultrasound (hydrops & Mid cerebral velocity MCV) Anti-D in HDFN Anti-D – Remains the most common cause of HDFN largely due to its high immunogenicity. Despite the introduction of the anti-D prophylaxis program in 1969, maternal sensitisation occurs in approximately 1000 Rh D Negative pregnancies annually. Rarely effects 1st pregnancies ….. WHY? Anti-K in HDFN Anti-K – 2nd most common cause of severe HDN. Characterised by severe HDN at low antibody concentrations due to the haemolysis of sensitised fetal red cells as well as erythroblasts which impacts compensatory erythropoiesis. Over 50% of antibodies are produced as a result of multiple transfusions with the remainder produced as a result of a previous pregnancy.  Anti-c – 3rd most common cause of severe HDN. Anti-c in HDFN Policy of providing R1R1 blood to c negative women of child bearing age by Welsh Blood Service who undertake large scale antenatal testing. How might we predict there’s a risk of HDFN? - Antibody Levels Quantitation: – Anti-D (mild 15iu/ml) – Anti-c (mild 20iu/ml) Titration – Anti-K - No cut-off titration but highlight increasing titres – Antibodies other than -D, -c, -K - No problems if titre score