Please enable JavaScript.

Coggle requires JavaScript to display documents.

Isoimmunization - Coggle Diagram

- - - - Allows direct evaluation of fetal hemoglobin, hematocrit, reitculocyte count, bilirubin
      - Used as adjunct when amniocentesis or MCA suggests anemia
      - Intrauterine transfusion if fetal anemia
  - - - Determined by intrauterine transfusions, induction of labour, C-section
    - - Phototherapy
        
        Most neonates with HDFN
      - RBC transufsion
        
        Treatment of anemia (Rh- RBcs)
      - Exchange tranfusipn
        
        Replace fetal Rh Positive RBCs, Hydrophic infant, severe neonatal icterus
- - - - Future pregnancies -> Antibodies may cross placenta
  - - - During delivery Rh antigens enters mothers ciruclation -> mother makes anti-rh antibodies -> Mother developes antibodies -> Anti-rh antibodies cancross placenta and destroy fetal blood cells
      - Pregnancy at risk
        
        Mother has antibodies known to cause HDFN
        
        Father is homozygous for antithetical antigen (100% chance that fetus expresses antigen) - Father heterozygous may not result in risk
      - Maternal RBC antibodies corss placental and destroy fetal RBCs
      - Implicated RBC antibodies: ABO, Rh-D, RH, Kell, Duffy, Kidd
- - - - Mother is A, B or O blood group, father expresses lacking ABO antigen, fetus inherits lacking antigen
    - - Most common cause of mild hemolysis
      - Resulting anemia is usually Mild
      - Most Anti-A and Anti-B antibodies are IgM and can't corss placenta
        
        Some IgG antibodiesdo occur and cross placenta
      - Affected infants do not have severe fetal anemia (mild anemia and jaundice is more common)
      - No Need for monitoring
      - Observation is essential since hyperbilirubinmia may require treatment
        
        Treatment includes phototherapy or exchange with Group O Blood (rare)
  - - - D is most important
      - RH Negative - D negative
        
        Absence of D-protein on RBC
      - D is highly immunogenic
        
        80% D positive RBc transfusion to D negative patient would result in antibody fomraiton
        
        Results in most common cause hemolytic disease of hewborn
      - Prevention of Maternal alloimmunization
        
        Highest risk among Rh- women
        
        Administration of anti-D immunogobulin during pregnancy reduces sensitization
        
        Binds to fetal Rh positive RBCs in maternal ciriculation and are removed by spleen prior to immune response
        
        given at 28 weeks and second dose given after delivery if infant is Rh positive
        
        FetoMaternal Hemorrhage
        
        Bleeding that leads to mixing of fetal and maternal blood
        
        Calculate % of fetal cells out of 200 and multiply by 50 to determine amount of fetal blood
        
        Dosing of RhIg
        
        One dose per 30 mL, and round up
        
        Contraindications
        
        Not administered to Rh(D) weak variants, in women with anti-D ANtibody, paitents with Hx of anaphylaxis to immune globulins, Patients hypersensitive to Anti-D, patients who refuse
        
        Further Management
        
        All women should have ABO and antibody screen during first trimester of pregnancy
        
        Identify women at risk of developing anti-D antibody
      - Determination of Fetal Genotype
        
        If rather is homozygous for D - 100% chance of D +ve fetus
        
        If father is heterozygous - Perform fetal genotyping
        
        Maternal cell free DNA
        
        Fetal RHD gene testing by amniocentesis
- - - - Previous transfusion, previous pregnancy