Hemolytic disease of newborn Lecture Final Year MBBS

Hemolytic disease of newborn lecture final yr mbbs

1. Hemolytic Disease of Newborn ( ERYTHROBLASTOSIS FETALIS ) Dr. Muhammad Sajjad Sabir MBBS , DCH, MCPS, FCPS Assistant Prof. Paediatrics

2. Hemolytic disease of newborn The term Hemolytic disease of the new born and fetus (HDN) is a destruction of the red blood cells (RBCs) of the fetus and neonate by antibodies produced by the mother

3. Hemolytic disease of newborn It is a condition in which the life span of the fetal/neonatal RBC is shortened due to maternal allo -antibodies against red cell antigens acquired from the father S O Rate of RBCs destruction is accelerated BUT ability of bone marrow to respond is NORMAL It was a major cause of fetal loss and death among newborn babies

4. Etiology Rh incompatibility: Hemolytic disease occurs most frequently develops when an Rh – ve mother conceives a fetus which is Rh + ve ABO incompatibility: mother has blood type O and the fetus has blood type A or B or AB Other causes: Other Minor blood group antigens( kell , kid ) Thalassemia Autoimmune Hemolytic Anemia

5. The Rh factor , Rh + and Rh - usually refers to presence or absence of antigen-D There are two alleles of antigen : D and d A person who is Rh - ve has two recessive traits, dd Anyone who has at least one D (DD or Dd ) is Rh +ve Rh -BLOOD GROUPING SYSTEM

6. Rh incompatibility: Rh incompatibility is a condition which develops when an Rh negative mother conceives a fetus which is Rh positive. Isoimmunization : When the mother produces Abs directed against fetus RBC surface Ag Cause Feto - maternal Bleed Risk Factors of Feto -maternal Bleed: Amniocentesis Ectopic pregnancy Fetal RBC Rh Antigen : Rh “ D ’’ Ag Mother produces: Anti Rh (D) Abs

7. PATHOGENISIS

8. DEFINITION: Rh incompatibility is a condition which develops when there is a difference in Rh blood type between that of the pregnant mother (Rh negative) and that of the fetus (Rh positive)

9. Rh Type and Pregnancy A person's Rh type is generally most relevant with respect to pregnancies If the pregnant woman is Rh - ve and her husband Rh +ve , there is possibility of Rh incompatibility If the pregnant woman and her husband are Rh negative, there is no reason to worry about Rh incompatibility

10. Usually placenta is barrier to fetal blood entering maternal circulation. Sometimes during pregnancy or birth , fetomaternal haemorrhage (FMH) can occur The woman’s immune system reacts by producing anti-D antibodies that cause sensitisation

11. Subsequent pregnancies antibodies can cross placenta and destroy fetal erythrocytes.

12. Conditions affecting 1 st pregnancy : Miscarriage Abortion Feto -maternal haemorrage The haemolytic disease of fetus and new born caused by Rh isoimmunisation can occur during the first pregnancy, but Usually sensitisation during the first pregnancy or birth leads to extensive destruction of fetal RBC during subsequent pregnancies

13. Pathogenesis Fetomaternal Hemorrhage Maternal Antibodies formed against fetus derived antigens During subsequent pregnancy, placental passage of maternal IgG antibodies Maternal antibody attaches to fetal red blood cells Fetal red blood cell hemolysis

14. Pathogenesis; before birth

15. Pathogenesis; after delivery

16. Clinical Presentation

17. Hemolysis → ↑ ed bilirubin levels Rh incompatibility can cause symptoms ranging from very mild to fatal . After delivery bilirubin is no longer cleared (via placenta ) from the neonate's blood → J aundice (within 24 hours of life) Possibility of acute or chronic Kernicterus

18. Sign &symptom Mildest form- Rh incompatibility: 1-Hemolysis with the release of free hemoglobin into the infant's circulation 2- Jaundice

19. Prenatal manifestations : Hydrops fetalis / Erythroblastosis Fetalis Massive fetal RBC destruction → Profound anemia pallor high-output heart failure ( CCF ) Enlarged liver / spleen Generalized Edema Ascites and Respiratory distress Severe form- Rh incompatibility

20. Severe form- Rh incompatibility 1- severe forms → petechiae and purpura 2- Severe anemia  Fetal heart failure  stillborn or Death of infant shortly after delivery

21. 2- Total body swelling 3- Respiratory distress (if infant has been delivered) 4- Circulatory collapse 5- Kernicterus . ( bilirubin encephalopathy) (Neurological syndrome in extremely high levels of indirect bilirubin ( >20 mg/ dL ). 6- It occurs several days after delivery and is characterized initially by... A) Loss of the Moro reflex. B) Poor Feeding . C) Decreased activity

22. LATER  At last it may lead to death of the child immediately after its birth

23. Investigations

24. Blood grouping Mother: Rh Negative Father : Rh Positive Baby : Rh Positive Direct Coombs test: Positive in INFANT Indirect Coombs test: Positive in MOTHER Biochemical test Hyperbilirubinemia Hypoalbuminemia LDH: Increase Haptoglobin Decrease

25. Blood Smear Polychromasia Anisocytosis ↑ Erythroblasts (nucleated RBCs) No S pherocytes CBC TLC: normal Hb : ↓ Hb MCV, MCH, HCHC : Normal or Increase Platelets: Normal to Decrease ↑ Reticulocytosis (6 to 40%)

26. Coombs test Direct Coombs test: diagnoses HDN The direct Coombs test detects maternal anti-D antibodies that have already bound to fetal RBCs This is called the direct Coombs test because the anti- Ig binds "directly" to the maternal anti-D Ig that coats fetal RBCs in HDN

27. Finds anti-D antibodies in mother's serum. If these were to come into contact with fetal RBCs they would hemolyse them and hence cause HDN. This is called the indirect Coombs test because the anti- Ig finds "indirect" evidence of harmful maternal antibodies, requiring the addition of fetal RBCs to show the capacity of maternal anti-D to bind to fetal RBCs Indirect Coombs test : used in the prevention of HDN

28. Management

29. If there is evidence of erythroblastosis Notify Pediatrics team for possibilitye delivery of a compromised newborn Management

30. Management Before birth( Antenatal ) options : Intrauterine RCC transfusion - blood transfused into fetal umbilical vein or Early induction of labor when Pulmonary maturity has been attained , Fetal distress is present, or 35 to 37 weeks of gestation have passed The mother may also undergo plasma exchange to reduce circulating levels of antibody by as much as 75 %

31. After birth( Postnatal ) Treatment depends on the severity of condition: Phototherapy Transfusion with compatible RCC, Exchange transfusion with a blood type compatible with both the infant and the mother Supportive care Temperature stabilization Monitoring Sodium bicarbonate ( correction of acidosis) O2/ assisted ventilation

32. Management: Phototherapy for neonate with mild jaundice Exchange transfusion in Severe cases

33. For Mother ( Antenatal ) Rh - ve mothers (pregnant with a Rh+ve infant are given) Rh immune globulin ( RhIG ) to prevent sensitization to D antigen RhoGAM protects against the effects of early transplacental hemorrhage (as recommended by the American College of Gynecologists). at 28 weeks during pregnancy at 34 weeks “ “ Plasma exchange to reduce circulating levels of antibody by as much as 75% Close monitoring of fetal well-being, as reflected by Rh titers, amniocentesis results, and sonography

34. For Mother ( Postenatal ) Rh - ve mothers with Rh+ve infant Inj RhoGAM must given within 72 hours of delivery of the newborn .

35. Preventing HDN Determine Rh status of the mother If the mother is not sensitized, reduce the risk of future sensitization If the mother is sensitized, determine whether the fetus is at risk and monitor accordingly To prevent Isoimmuization of yet unimmunized mother give Anti Rh D IgG ( Rhogam ) IntraMuscular at 28 weeks of gestation.

36. Summary:

37. THANK YOU