RED CELL ALLOIMMUNIZATION by Dr. Zamiul Hasan Fahim.pptx

All about red cell alloimmunization regarding Rh incompatibility causing hemolytic disease of the newborn.

1. RED CELL ALLOIMMUNIZATION Presented by Dr. Tumpa Biswas & Dr. Shamima Akter Provati Department of Obs. & Gynae of BGCTMC Hospital .

2. HISTORY The Rhesus (Rh) blood group system was discovered by Landsteiner and Wiener in 1940 by producing immune antibodies in rabbits after injecting blood from the rhesus monkey reacted with about 85% of human red blood cells; Believing the observation described they named the blood group  after the rhesus monkey. Rh alloimmunization in pregnancy develops when the maternal red blood cells(RBCs) lacking the Rh antigen ( RhD negative) are exposed to RhD positive RBCs through the placenta leading to the activation of the maternal immune system.

3. Basic Blood Groups 2 most important blood group systems: ABO group Rhesus group

4. ABO BLOOD GROUP

5. Rhesus BLOOD GROUP

6. EPIDEMIOLOGY Globally incidence of Rh negativity 30-35% Otherwise, Europeans & American Whites : 15-17% In India & Bangladesh : 5-10% In china : 1% In Japan : Almost nil .

7. GENOTYPES The complete genetic makeup of the Rh blood group of an individual is its Genotype. Gene coding for Rh antigen is located on CH-1p(short arm of chromosome 1). Rh antigen is present in the RBCs as early as 38 days of gestation. Major Antigens are D, C, c, E, e, G. Presence or absence of D antigen is used to designate one as Rh+ve or Rh- ve .

8. Continue... An individual carrying D on both sets of antigens (DD) is called homozygous . An individual carrying D only (Dd) in one set, is called heterozygous.

9. definition Alloimunization is defined as a production of immune antibodies in an individual in response to a foreign red cell antigen derived from another individual of the same species provided; the first one lacks the antigen. It occurs in two stages. 1. Sensitization 2. Immunization (At least 0.1ml of fetal blood enters the maternal circulation)

10. Methods of Alloimmunization Two Methods of Alloimmunization : Pregnancy: (Rh positive women bearing a Rh-positive fetus ) the following conditions where the risk of fetomaternal bleed is present: miscarriage, MTP, genetic amniocentesis, ectopic pregnacy , H. mole, cordocentesis, CVS, placenta previa with bleeding, placenta abruption, IUFD, ECV, Abdominal trauma, during delivery (15-50%), following C/S & manual removal of placenta. 2. Transfusion of mismatched blood.

11. Pathophysiology of rh isoimmunization

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14. Volume of FMH (ml) Risk of Sensitization (%) 0.1 3 0.2-1 25 >5 65 Risk of sensitization in relation to volume of FMH

15. Complications of fetal Neonatal Anaemia Hydrops fetalis & IUFD Hepatosplenomegaly Neonatal Jaundice Complications of Neonatal Kernicterus (Lethargy, Hypertonicity, Hearing Loss, Cerebral Palsy, Learning Disability) Neonatal anaemia

16. Pathogenesis of erythroblastosis fetalis

17. fetal effects of isoimmunization Clinical manifestation of the hemolytic disease of the fetus and newborn are: 1. Hydrops fetalis 2. Icterus gravis neonatorum 3. Congenital anaemia of the newborn .

18. Hemolytic disease of the fetus & newborn

19. Hydrops fetalis

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21. Icterus gravis neonatorum Lesser form of HDFN ( Hemolytic Disease of Fetus & Newborn ) Baby is born alive without evidence of jaundice but soon develops it within 24 hours of birth If bilirubin rises to critical level of 20mg per 100ml(340µmol/L), Bilirubin crosses blood brain barrier to damage the basal nuclei of the brain permanently→Kernicterous .

22. Congenital anaemia of newborn Mildest form of the disease ( hemolysis is going slowly). Jaundice is not usually evident. Hemolysis continues up to 6weeks after antibodies are not available for hemolysis . Liver & spleen enlarged (sites of extramedullary erythropoiesis ).

23. Diagnostic features

24. Maternal effect Pre- eclampsia Polyhydramnios Big size baby with its hazards Hypofibrinogenemia due to prolonged retention of dead fetus in uterus Postpartum hemorrhage due to big placenta and blood coagulopathy Maternal syndrome

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26. Prevention

27. To prevent active immunization

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29. To prevent or minimize fetomaternal bleed

30. Antenatal investigations Blood grouping of patient:

31. Continue....... If the husband is Rh positive, further investigations are to be carried out which aim at: To detect whether the woman has already been immunized to Rh antigen. To forecast the likely affection of the baby To anticipate and formulate the line of management of a likely affected baby. Detailed Obstetric history in primigravida with no previous history of blood tranfusion or multigravida including previous baby detail & anti-D.

32. Diagnosis of rh isoimmunization

33. Diagnosis of maternal isoimmunization

34. Continue..... Antibody detection: IgG antibody is detected by Indirect Coomb’s Test. If the test is found negative at 12th week, it is to be repeated at 20 th wk, 28 th wk, and 36 th wk in a primigravida. In a multigravida, the test is to be repeated at monthly interval upto 24th week and at every 2 wks thereafter.

35. Continue..... If the test is found positive :

36. Methods of diagnosis & evaluation of fetal rh isoimmunization

37. Plan of delivery Unimmunized mothers- if no antibody found expected management till term. Don’t allow to overrun EDD. Immunized mother: Methods of delivery - vaginal, LSCS Care during delivery- In vaginal delivery: Careful fetal monitoring. Prophylactic ergometrine during second stage should be withheld. Gentle handling of the uterus in the 3 rd stage. To take care of PPH.

38. Continue...... In Cesarean section: To avoid spillage of blood into the peritoneal cavity. Routine manual removal of placenta should be withheld. Clamping the umbilical cord as quickly as possible. The cord should be kept long for exchange tranfusion , if required. Collection of cord blood for investigation: Sample is taken from placental end of the cut cord. A bout 5 ml blood(2ml oxalated and 3ml clotted) should be collected for following test: Clotted blood: ABO and Rh typing, Reticulocyte count, Direct coomb’s test and serum bilirubin . Oxalated blood: Haemoglobin estimation and blood smear for presence of immature RBC.

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40. Methods of blood transfusion in fetus Intrauterine transfusion which includes intraperitoneal and intravascular transfusion. Plasmapheresis . High dose IVIG(Intravenous Immunoglobulin) Exchange transfusion.

41. Prognosis With alloimmunization of mother prognosis of the baby depends on- Genotype of father, genotype of fetus , maternal antibody levels, history of previous affection of baby due to hemolytic disease, availability of advanced diagnostic facilities for affected babies. Due to advanced management protocols the baby survival rate is 100%. No contraindications of breast feeding.

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43. Thank you