Case Study 3 – Hemolytic Disease of the Newborn (Erythroblastosis fetalis)

Study Questions

 

  1. Before a blood transfusion the recipient is typed first and cross-matched with the donor blood.  What is a cross-match and why is it done?

 

  1. Why is HDN more of an issue in subsequent pregnancies and not the first pregnancy?

 

  1. Why are IgG anti-Rh antibodies less likely to agglutinate Rh+ rbcÕs than IgM anti-Rh antibodies?

 

  1. What is the CoombÕs test and how does it solve the issue described in question #3 above?

 

  1. What are the reagents used in the Coombs test?  How does the direct test differ from the indirect test?  How is the test read?

 

  1. What is the standard length of human pregnancy in weeks?

 

  1. What is the significance of an increased bilirubin level in the amniotic fluid?

 

  1. Why would they give the fetus ÒO, Rh negÓ cells rather than matched cells?

 

  1. How are the rbcÕs destroyed in the fetus?

 

  1. Why is an ABO incompatible fetus less of a problem than an Rh incompatible one?