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Comprehensive training presentation by iTransfuse with the London RTC on Blood Grouping & Antibody Testing in Pregnancy. Understand the tests required during pregnancy, importance of antibodies, and necessary post-delivery tests. Explore protocols, clinically significant antibodies, immune vs. prophylactic anti-D, and future developments in foetal blood group testing. Ideal for healthcare professionals.
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Blood Grouping and Antibody Testing in Pregnancy Training Presentation by iTransfuse with the London RTC Based on the BCSH Guideline for Blood Grouping and Antibody Testing in Pregnancy 2006
Aim • By the end of this you should have an understanding of: • The tests required during pregnancy • Why we do the tests • What antibodies are significant • What tests are required post delivery
Purpose of Lab Testing • ABO and D typing to identify D negative women who need anti-D • Antibody screening and ID of red cell alloantibodies • Monitor circulating levels of clinically significant antibodies
Antenatal Testing Protocols • Booking sample testing (ABO and antibody screen) • ideally at 10-16 weeks gestation • Repeat test at 28 weeks gestation (ABO and antibody screen) • If antibody screen is positive a full antibody investigation must be performed
Clinically Significant Antibodies • What antibodies are implicated in severe HDN? • Anti-D • Anti-c • Anti-K • In addition to these anti-C, -E, -Fya and Jka • Only IgG antibodies are capable of entering the foetal circulation
Women with anti-D • How can you distinguish between prophylactic and immune? • Check transfusion records • Previous prophylactic anti-D given (within 8 weeks) • Antibody history? • Phone ward/GP to check if patient transferred • Send for D Quantitation • Anti-D level rarely exceeds 1 iu/ml post prophylaxis unless a dose of more than 1250 iu has been administered
Immune Anti-D • How often should you test during pregnancy? • Every 4 weeks until 28 weeks gestation then every 2 weeks until delivery • What testing should be done? • Maternal Rh phenotyping • Anti-D quantitation (every maternal sample) • Partner sample phenotyping • Refer patient to Obstetric team
Concentration of Anti-D • What levels of anti-D are significant?
Women with anti-c • How often should you test during pregnancy? • Every 4 weeks until 28 weeks gestation then every 2 weeks until delivery • What testing should be done? • Maternal Rh phenotyping • Anti-c quantitation (every maternal sample) • Partner Rh phenotyping • Refer patient to Obstetric team
Concentration of Anti-c • What levels of anti-c are significant?
Women with anti-K • How often should you test during pregnancy? • Every 4 weeks until 28 weeks gestation then every 2 weeks until delivery • What testing should be done? • Maternal Kell phenotyping • Anti-K Titre (every maternal sample) • Partner Kell phenotyping • Refer patient to Obstetric team
Women with other red cell antibodies • Anti-C, -E, -Fya and –Jka are other antibodies most associated with HDN • Other blood group antibodies have been implicated in HND
Women with other red cell antibodies • How often should you test during pregnancy? • Booking and 28 weeks • What testing should be done? • Antibody investigation • Maternal phenotyping • Titre the antibody against previous sample • Partner phenotyping • Refer patient to Obstetric team
Paternal Testing • Why do it? • Helps predict the likelihood of the foetus carrying the relevant red cell antigen • For example. Maternal phenotype c- and anti-c detected. Paternal phenotype Cc. Foetus has 50% change of carrying antigen. • Caution – is the partner the father?
Foetal Genotyping • When should you send samples? • When a clinically significant antibody of high concentration is present • Women has history of HDN and father is heterozygous for relevant antigen • What antigen(s) can be determined? • D • c • K • (E)
At Delivery – D negative women with no immune anti-D • What samples are required? • Maternal and Cord blood • What tests should be done? • ABO and Rh typing on both samples • FMH estimation (flow cytometry / Kleihauer) • DAT? • When do you give anti-D prophylaxis? • When baby is RhD positive
Future Developments • Mass testing for foetal blood group antenatal for RhD negative women • If done before 28 weeks it would prevent the use of anti-D prophylaxis in women carrying RhD negative foetus’s
Acknowledgement • This educational resource has been produced to support education and training by the London RTC Education Resource group. • Please acknowledge the working group when using or adapting this presentation during delivery. • Please contact the RTC Education Resource group if you have ideas for other presentations or would like to be involved. • Thank you