Hemolytic Disease of the Fetus and Newborn (HDFN)

Question 1

1. The etiology of HDFN is characterized by:
   a. IgM antibody
   b. Nearly always anti-D
   c. Different RBC antigens between mother and father
   d. Antibody titer less than 32

Answer 1

c. Different RBC antigens between mother and father

Question 2

2. An important difference between the fetus and the
   newborn physiology is:
   a. Bilirubin metabolism
   b. Maternal antibody level
   c. Presence of anemia
   d. Size of RBCs

Answer 2

a. Bilirubin metabolism

Question 3

3. Kernicterus is caused by the effects of:
   a. Anemia
   b. Unconjugated bilirubin
   c. Antibody specificity
   d. Antibody titer

Answer 3

b. Unconjugated bilirubin

Question 4

4. The advantage of middle cerebral artery peak systolic
   velocity Doppler (MCA-PSV) is that it is:
   a. Able to measure fetal hemoglobin and hematocrit
   levels
   b. Able to support antigen typing of fetal blood using
   DNA
   c. Helpful for direct transfusion of fetal circulation
   d. Noninvasive and decreases risk of adverse events

Answer 4

d. Noninvasive and decreases risk of adverse events

Question 5

5. Blood for intrauterine transfusion (IUT) should be:
   a. Irradiated, leukocyte reduced, more than 7 days old,
   HbS negative
   b. Irradiated, leukocyte reduced, less than 7 days old,
   HbS positive
   c. Irradiated, leukocyte reduced, less than 7 days old,
   HbS negative
   d. Irradiated, leukocyte reduced, more than 7 days old,
   HbS positive

Answer 5

c. Irradiated, leukocyte reduced, less than 7 days old,
HbS negative

Question 6

6. RhIG is indicated for:
   a. Mothers who have anti-D due to allosensitization
   b. Infants who are RhD-negative
   c. Infants who have anti-D
   d. Mothers who are RhD-negative

Answer 6

d. Mothers who are RhD-negative

Question 7

7. RhIG is given to RhD-negative mothers without regard
   for fetal RhD type in all of the following conditions
   except:
   a. Ectopic pregnancy rupture
   b. Full-term delivery
   c. Amniocentesis
   d. Induced abortion

Answer 7

b. Full-term delivery

Question 8

8. A Kleihauer-Betke test or flow cytometry indicates 10 fetal
   cells per 1,000 adult cells. For a woman with 5,000-mL
   blood volume, the proper dose of RhIG is:
   a. One regular-dose (300 µg) vial
   b. Two regular-dose vials
   c. Three regular-dose vials
   d. Four regular-dose vials

Answer 8

c. Three regular-dose vials

Question 9

9. ABO HDFN is usually mild because:
   a. ABO antigens are poorly developed in the fetus
   b. ABO antibodies prevent the disease itself
   c. ABO antibodies readily cross the placenta
   d. ABO incompatibility is rare

Answer 9

a. ABO antigens are poorly developed in the fetus

Question 10

10. A woman without prenatal care delivers a healthy term
    infant. A cord blood sample shows the infant is A-positive
    with a positive DAT. The workup of the unexpected finding should include:
    a. Anti-C3 antiglobulin test
    b. ABO testing of the mother
    c. Direct antiglobulin testing of the mother’s specimen
    d. ABO and Rh typing of the father

Answer 10

b. ABO testing of the mother