HDFN

Question 1

What is HDFN ?

Answer 1

maternal red cell antibodies (IgG) cross placenta and attach to fetal cells = hemolysis

Question 2

Symptoms of fetus in HDFN

Answer 2

• anemia
• increased erythropoiesis aka “Erythroblastosis fetalis”
• severity depends on antibody ID and concentration

Question 3

Factors of maternal Ab production (5)

Answer 3

1. amount of blood exposure (0.5 mL vs 25 mL)
2. immunogenicity of antigen (D vs Fya)
3. previous exposure (primary vs secondary)
4. maternal immune response (responder vs. non-responder)
5. ABO compatibility

Question 4

severe cases of HDFN (in utero)

Answer 4

• profound anemia
• hepatosplenomegaly
• hypoproteinemia
• cardiovascular failure (heart enlarged bc decrease in RBC mass)
• “Hydrops fetalis” severe edema = infant dies in utero