HDFN & Hemolytic Anemias Flashcards
(84 cards)
What is the definition of hemolytic disease of the fetus and newborn (HDFN)?
Results from immune destruction of RBCs of fetus or newborn due to sensitization by the mother’s IgG antibody
Maternal antibody crosses the placenta and reacts with an RBC antigen inherited from the father.
What are the criteria necessary for HDFN to develop?
Mother must be sensitized to fetal RBC antigens, typically through previous pregnancy or transfusion.
What are the three classifications of HDFN?
- Rh
- ABO
- Other/non-Rh antibodies
How does bilirubin metabolism differ in the fetus versus the newborn?
In the fetus, bilirubin is conjugated in the maternal liver; in the newborn, the liver is unable to conjugate large amounts of bilirubin.
What are the intervention procedures used in the diagnosis and management of HDFN?
Includes laboratory testing, monitoring bilirubin levels, and possible transfusions.
What treatments are available for HDFN?
Includes phototherapy, exchange transfusion, and administration of Rh immune globulin.
What blood components are preferred for intrauterine or exchange transfusions?
Red blood cells, preferably less than 7 days old.
What is Rh Immune Globulin (RhIG)?
A medication used to prevent Rh sensitization in Rh-negative mothers.
What are the key aspects of administering RhIG?
- Dosage
- Eligibility criteria
- Timing intervals
What does a positive rosette test indicate?
Suggests fetomaternal hemorrhage.
What is the significance of the Kleihauer-Betke test?
Used to quantify fetal-maternal hemorrhage.
What is an autoantibody?
An antibody produced by the immune system that targets the body’s own cells.
What are the types of immune hemolytic anemias?
- Warm autoimmune hemolytic anemia (WAIHA)
- Cold agglutinin disease
- Drug-induced hemolytic anemia
What are pathologic cold autoagglutinins?
Antibodies that cause agglutination at lower temperatures, leading to hemolysis.
What complications can arise from HDFN during pregnancy?
- Mild anemia
- Hyperbilirubinemia
- Jaundice
- Severe enlargement of the liver and spleen
- Hydrops fetalis
What is kernicterus?
A severe condition resulting from high levels of unconjugated bilirubin affecting the brain.
What occurs when fetal RBCs are destroyed?
Anemia limits oxygen carrying ability, leading to compensatory erythropoiesis in the liver and spleen.
What is hydrops fetalis?
A condition where the fetus accumulates fluid due to severe anemia.
What is the role of glucuronyl transferase in bilirubin metabolism?
Converts indirect bilirubin to a conjugated form in the liver.
What laboratory findings indicate severe HDFN?
Elevated indirect bilirubin levels and positive direct antiglobulin test (DAT).
What is the primary characteristic of moderately affected D-positive infants?
Jaundice develops within the first few days of life.
What is the treatment required in cases of Rh HDFN?
Exchange transfusion to prevent kernicterus.
What is the most common form of HDFN?
ABO HDFN.
Is ABO HDFN preventable?
No, it can affect the first pregnancy.