Dr. Afaf I. Alnoury RHESUS INCOMPATIBILITY بسم الله الرحمن الرحـيـم

Dr. Afaf I. Alnoury MATERNAL BLOOD GROUP IMMUNIZATION Hemolytic Disease (Erythroblastosis Fetalis) The Rh Group system:  The Rh blood group system is the most common & most important blood group system causes immunization & hemolytic disease. Fisher’s Theory  The Rh antigen are grouped in three pairs &.  The Rh antigen are grouped in three pairs Dd, Cc & Ee.  The presence of determined that the individual is Rh +ve.  The presence of D determined that the individual is Rh +ve.  The absence of D that determine that a person is.  The absence of D that determine that a person is Rh D –ve.  45% of Rh +ve individual are homozygous.  55% of Rh +ve individual are heterozygous. RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Blood transfusion Fetal Maternal Transplacental Hemorrhage (TPH) RHESUS INCOMPATIBILITY The Pathogenesis of Maternal Blood Group Immunization

Dr. Afaf I. Alnoury RHESUS INCOMPATIBILITY The Pathogenesis of Maternal Blood Group Immunization

Dr. Afaf I. Alnoury Incidence Of Rh immunization Amount of antigen necessary to produce Rh immunization: The incidence of Rh immunization is dose dependent.  15% became immunized after 1 ml of Rh+ve red cell.  33% became immunized after 40 ml of Rh+ve red cell.  65% became immunized after 250 ml of Rh+ve red cell.  The secondary immune response is provoked by very small amount of Rh+ve blood ( ml of red cells) RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Pathogenesis of Hemolytic Disease of fetus & newborn (HDN) The basic pathogenesis of HDN is the destruction of Rh+ve fetal red cells by maternal Rh antibody (IgG anti D). RBC destruction, fetal anemia   production of fetal erythropoietin  bone marrow produce  RBC’s  extramedullary organs (liver, spleen, kidney & adrenal) to produce  RBC’s  Hepatosplenomegaly  Nucleated red cells elements appear in fetal circulation (normoblast, erythroblasts)   erythroblastosis faetalis RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Severity of Rh hemolytic disease Mild: Indirect bilirubin does not exceed mg/100ml Indirect bilirubin does not exceed mg/100ml No anemia50% No anemia50% No treatment No treatmentModerate: Fetal hydrops doesn't develop Fetal hydrops doesn't develop Moderate anemia30% Moderate anemia30% severe jaundice with risk of kernicterus unless treated severe jaundice with risk of kernicterus unless treatedSevere: Fetal hydrops develop in utero Fetal hydrops develop in utero Before 34 weeks10 – 12% After 34 weeks10 – 12% RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Prediction Severity of Rh hemolytic disease History of fetus or infant with Rh disease Maternal Rh antibody measurement Amniocentesis  amniotic fluid optical density measurement RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Management of the Rh hemolytic disease First visit: ABO, antibody screening test ABO, antibody screening testRh-ve RHESUS INCOMPATIBILITY Intrauterine fetal transfusion Extrauterine Fetal transfusion Follow up

Dr. Afaf I. Alnoury Management of the Rh hemolytic disease Husband Rh RHESUS INCOMPATIBILITY Rh - ve+ ve Mother Blood gp O 66.5% chance of ABO Incompatibility Decrease the risk of Rh immunization From 16% to 1.5% Heterozygous 50% chance Rh –ve fetus

Dr. Afaf I. Alnoury Amniocentesis Indications:Timing:Technique:Hazards: RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Intrauterine fetal transfusion Indications:Technique: Intraperitoneal fetal transfusion (IPT) Intraperitoneal fetal transfusion (IPT) Direct intravascular transfusion (IVT) Direct intravascular transfusion (IVT)Hazards: Maternal MaternalInfectionTrauma Fetal Fetal Over transfusion Cardiac tamponade Infection Precipitation of labour Umbilical vein compression RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Prevention Every Rh –ve unimmunized women who deliveries on Rh +ve baby should be given a prophylactic dose of Rh IG as soon after delivery as possible. Every Rh –ve unimmunized women who aborts should have at least 50 μg of Rh IG. Every Rh –ve unimmunized women undergoing amniocentesis should be given one prophylactic dose of Rh IG. RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury Prevention cont. One prophylactic dose of Rh –ve unimmunized pregnant women at 28 weeks gestation. IF MASSIVE TRANSPLACENTAL HEMORRHAGE OF Rh +ve fetal red cells into an Rh –ve unimmunized women is diagnosed after delivery, one prophylactic dose of Rh IG should be given for every 25 ml of fetal blood and fraction. RHESUS INCOMPATIBILITY

Dr. Afaf I. Alnoury RHESUS INCOMPATIBILITY