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Rhesus incompatibility

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Rhesus incompatibility

  1. 1. Presented by: Group 86 Chow Jun Wing Lui Siau Ting
  2. 2. • A condition that occurs during pregnancy if a blood and her blood. Mother’s body create Rh antibodies against the baby’s blood. • Also known as haemolytic disease of the fetus and newborn(HDFN). Oct-15 2Rhesus Incompatibility
  3. 3. Introduction • Rh-Ag are found on the surfaces of the RBCs may cause isoimmunization. • System used to designate Rh-Ag is the Fisher CDE system. • D-antigen, the most powerful Rh factor. possess it- Rh +ve ; lack- Rh –ve • Exposure of Rh-ve ppl to even small amounts of Rh+ve cells can result in the production of anti-D alloantibody– Rh sensitization/isoimmunization Oct-15 Rhesus Incompatibility 3
  4. 4. Pathogenesis Oct-15 Rhesus Incompatibility 4 1. Rh-ve mother carrying Rh+ve fetus 2. Entry of fetus Rh+ve RBC into maternal circulation 3. Development of Rh antibodies by the mother
  5. 5. 1. Rh-ve mother carrying Rh+ve fetus • The chance of having Rh+ve fetus from Rh+ve father ranges from 50% (if the father is heterozygous) to 100% (if the father is homozygous). • Non paternity explains the development of hemolytic disease of the newborn. Oct-15 Rhesus Incompatibility 5
  6. 6. 2. Entry of the fetal Rh+ve RBC into maternal circulation • Transfusion of incompatible blood (rare) • Fetomaternal hemorrhage(through leaks in the placenta- 3rd stage):  Spontaneous/ induced abortion  Ectopic gestation  Antepartum hemorrhage: abruptio placenta, amniocentesis, abdominal trauma, external cephalic version. • Worsen fetomaternal bleeding during labour are manual removal of placenta, twin delivery and caeserian section. • Fetal RBC are detected in the maternal circulation in 6% in the 1st trimester, 15% in the 2nd trimester and 30% in the 3rd trimester. Oct-15 Rhesus Incompatibility 6
  7. 7. 3. Development of Rh antibodies by the mother • Initially – Ig M (big Ig can’t pass the placental barrier). • Fetomaternal bleeding in the subsequent pregnancies results in the anamenstic reaction producing Ig G (can pass placental barrier) • Transfer of Ig G develops hemolytic disease of the newborn and hydrops fetalis, antibodies mediated destruction of the fetal RBCs. • First neonate is usually spared but subsequent Rh +ve fetuses are affected. Oct-15 Rhesus Incompatibility 7
  8. 8. Risks of Rh incompatibility effect Oct-15 Rhesus Incompatibility 8 Rh+ve father Rh-ve mother 1st Rh+ve baby Usually unaffected Rh+ve cells Miscarriage/ Termination of pregnancy Ectopic pregnancy Amniocentesis Antepartum haemorrhage Delivery of placenta Rhesus antibodies Pass to 2nd Rh+ve baby Hemolysis of Rh +ve cells Fetal Anemia Hydrops fetalisIntrauterine transfusion Postnatal exchange transfusionTreatment
  9. 9. Effects on the fetus and the newborn • Hemolytic anemia • Progressive anemia which eventually leads to congestive HF and tissue hypoxia • Portal HPT ~ obstruction of the portal veins • Hydrop fetalis- generalized edema • Kernicterus- unconjugated bilirubin crosses the BBB and damages the basal ganglia • Jaundice-⬆bilirubin in infant’s blood Oct-15 9Rhesus Incompatibility
  10. 10. Signs in an unborn baby • If the baby develops rhesus disease while still in the womb, they may become anaemic because their RBCs are being destroyed faster than usual by the antibodies. If the anaemic is severe, internal swelling may result. Oct-15 10Rhesus Incompatibility
  11. 11. Signs in a newborn baby • Hemolytic anemia ₋ Pale, ₋ increased breathing rate, ₋ poor feeding • Jaundice ₋ Dark skin ₋ Yellow sclera, palms and soles • Kernicterus ₋ Motor sensory and mental deficiencies Oct-15 Rhesus Incompatibility 11
  12. 12. Complications • Repetitive miscarriage • Fetal anemia • Hydrop fetalis • Intrauterine fetal death Oct-15 12Rhesus Incompatibility
  13. 13. Investigations: • At the first antenatal visit, all women are screened for blood and Rh type. • If a woman has Rh-negative blood, the paternal blood type and zygosity (if paternity is certain) are determined. If the father has Rh-positive blood, maternal Rh antibody titres are measured at 26 to 28 weeks. • Maternal serum antibody titre is a guide to disease severity. Oct-15 Rhesus Incompatibility 13
  14. 14. Investigations: • If antibody levels rise, the baby should be examined for signs of anaemia. • Fetal middle cerebral artery (MCA) blood flow is measured at intervals of 1 to 2 weeks depending on titres and patient history. The purpose is to detect high-output heart failure and fetal anaemia. • Using MCA doppler: the peak of MCA velocity – Rise - high probability of anemia Oct-15 Rhesus Incompatibility 14 Anti-D level Outcome <4IU/mL HDFN unlikely 4-15IU/mL Moderate risk of HDFN >15IU/mL High risk of hydrops fetalis
  15. 15. • Spectral photometry of amniotic fluid - used to measure the level of bilirubin as an indirect indicator of fetal haemolysis. • Ultrasound examination of the fetus at risk for Rh incompatibility may reveal subcutaneous oedema, ascites, pleural effusion, or pericardial effusion, all of which are consistent with severe fetal anaemia in an affected fetus. • A rosette test can be used to rule out significant fetomaternal haemorrhage. If results are positive, a Kleihauer-Betke (acid elution) test or flow cytometry can measure the amount of fetal blood in the maternal circulation. Oct-15 Rhesus Incompatibility 15 Investigations:
  16. 16. Management Management Unsensitized pregnancy Identification Management Sensitized pregnancy Management Oct-15 16Rhesus Incompatibility
  17. 17. Management of Rh-ve unsensitized pregnancy I. Identification of pregnancies at risk at the initial ANC visit. – Determine blood group & Rh factor and indirect coombs test for antibody screening for all pregnant mothers. II. Management of unsensitized pregnancy • Repeat indirect coombs test at 28 weeks and at 36 weeks. If negative consider antepartum prophylaxis with 300 micrograms of anti D gamma globulin at 28 weeks. If positive manage as sensitized pregnancy. Oct-15 17Rhesus Incompatibility
  18. 18. Management of Rh-ve unsensitized pregnancy • Provide anti D prophylaxis in cases with amniocentesis, APH, external cephalic version. • Following delivery determine blood group of the newborn and antibody screening. If the newborn is Rh negative no further treatment is needed. If antibody screen is positive monitor the newborn for haemolysis and manage next pregnancy as sensitized. If newborn is Rh negative and antibody screen is negative, provide anti D gamma globulin within 72 hours. The usual dose is 300 micrograms but ideally should be determined by the extent of fetomaternal hemorrhage. This is done by performing Kleihauer Betke test (acid elusion test). For abortion of less than 12 weeks gestation the dose is 50 micrograms. Oct-15 18Rhesus Incompatibility
  19. 19. Management of sensitized mother Oct-15 19Rhesus Incompatibility • Measurement of antibody levels in titers at regular intervals, • Amniocentesis for bilirubin levels • Serial ultrasound for detection of hydrops and management of neonatal anemia and hyperbilirubinemia. • Therefore, referral of these women is the correct approach at health center level.
  20. 20. Treatment • Intrauterine transfusion • Elect time of delivery • Exchange transfusion after delivery • Phototherapy after delivery • Top-up transfusion (Hb falls below 7g/dl, prophylactic :oral folate) Oct-15 20Rhesus Incompatibility
  21. 21. Intrauterine transfusion • The fetus can die in utero from severe anaemia and hydrops before he can be delivered. • An intrauterine transfusion can prolong the life in utero of a fetus to a gestation where the risks of prematurity are estimated as being less than those of the Rh disease. This can be done by an: 1. Intraperitoneal transfusion guided by ultrasound. 2. Umbilical vein transfusion guided by ultrasound. • Rh-negative blood is either transfused under ultrasound control. Repeat as necessary, according to amniotic optical density, or fetal haematocrit. The intravenous route is becoming increasingly the preferred method. Oct-15 Rhesus Incompatibility 21
  22. 22. Choose time of induction and best method of delivery • Balance the risks of prematurity (too soon) with that of worsening Rh disease (too late). • Consider the risks of vaginal delivery and be prepared for a lower segment Caesarean section (LSCS). • Usually done only after 34 weeks of gestation. • The paediatric team should be in close and a senior paediatrician present at the delivery • fresh Rh-negative blood available. Oct-15 Rhesus Incompatibility 22
  23. 23. Resuscitation and Exchange transfusion • Good resuscitation is essential. In an anaemic and premature infant, lung disease is common. It can be due to:  Surfactant deficiency at very early delivery.  Pulmonary oedema from anaemia and hypoproteinaemia.  Hypoplastic lungs secondary to pleural effusions. • In severe Rh haemolytic disease of the newborn, an umbilical artery catheter should be inserted as soon as possible to assess and control PaO2 and pH. • Central venous pressure should be measured.  Drain pleural effusions and ascites at resuscitation. Oct-15 Rhesus Incompatibility 23
  24. 24. Indication for exchange Transfusion: 1. Early: Decision mainly based on cord haemoglobin (in addition consider history of previously affected babies). • Cord haemoglobin <12g/dl. • Strongly positive Coombs’ test. • Cord bilirubin >85mmol/l. 2. Late: Usually done for hyperbilirubinaemia. • The aims:  Treat anaemia.  Washes out IgG antibodies.  Decreases degree of haemolysis.  Removes bilirubin.  Prevents kernicterus. Oct-15 Rhesus Incompatibility 24 Resuscitation and Exchange transfusion
  25. 25. Phototherapy • Placing newborn baby under a halogen or fluorescent lamp with their eyes covered. • Lowers the bilirubin levels in the baby’s blood through photo-oxidation. • During phototherapy, intravenous hydration is required. Oct-15 Rhesus Incompatibility 25
  26. 26. Prevention and Prophylaxis • anti-D immunoglobulin to all Rh-negative women at 28 and 34 weeks routinely-RAADP; • Or give anti-D immunoglobulin if she has a:  Therapeutic abortion. Spontaneous abortion/ectopic pregnancy.  Amniocentesis.  Any bleeding in pregnancy/threatened miscarriage.  ECV.  After delivery at any gestation within 72Hours. Oct-15 26Rhesus Incompatibility
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