Deck 19: Hemolytic Disease of the Fetus and Newborn

Question 1

A cord blood specimen from a jaundiced infant should be tested for which of the following?

A) ABO
B) Rh
C) DAT
D) All of the above

Answer 1

D

Question 2

Due to a short supply of O-negative packed cells, an Rh-negative patient was transfused with 1 unit of Rh-positive red blood cells. Calculate the number of Rh-immune globulin vials needed to protect against 250 mL of Rh-positive packed cells.

A) 5
B) 17
C) 10
D) 23

Answer 2

B

Question 3

Which severe outcome can be caused by indirect bilirubin levels greater than 18 mg/dL in the newborn?

A) Hydrops fetalis
B) Kernicterus
C) Bilirubinemia
D) Bilirubinuria

Answer 3

B

Question 4

An O-positive mother gave birth to an A- negative baby. After 24 hours the newborn's bilirubin level rose to 18 mg/dL. A DAT performed on the cord blood specimen was positive with polyspecific AHG and anti-IgG reagents. It is probable that ___________from maternal circulation is coating the newborn's red blood cells.

A) anti-A, B
B) anti-B
C) anti-A
D) anti-D

Question 5

What is the physiological mechanism of Rh-immune globulin?

A) Attachment of fetal Rh-positive red blood cells in fetal circulation, inhibiting production of anti-D
B) Attachment of maternal Rh-negative red blood cells in maternal circulation, inhibiting production of anti-D
C) Attachment of fetal Rh-positive red blood cells in maternal circulation, inhibiting production of anti-D
D) Attachment of fetal Rh-negative red blood cells in maternal circulation, inhibiting production of anti-D

Question 6

Which of the following best describes the principle of the Kleihauer-Betke test?

A) D-positive indicator cells form rosettes around maternal Rh-positive RBCs
B) D-positive indicator cells form rosettes around fetal Rh-positive red blood cells
C) Maternal hemoglobin is resistant to acid (alkali), appearing pink, whereas fetal cells appear as ghost cells
D) Fetal hemoglobin is resistant to acid (alkali) and appears pink, whereas maternal red blood cells appear as ghost cells

Question 7

In HDFN, the IgG antibodies are directed against which antigen on the fetal red blood cells?

A) Maternal
B) Paternal
C) Bacterial
D) Viral

Question 8

What tests are indicated for cord blood specimens if the mother has made anti-K?

A) ABO, Rh, Antibody screen
B) ABO, Rh, DAT
C) ABO, Rh, cold autoabsorption
D) Kleihauer-Betke

Question 9

Which of the following treatments uses ultraviolet light to treat hyperbilirubinemia after the infant is delivered?

A) Phototherapy
B) Plasma exchange
C) Amniocentesis
D) Electrophoresis

Question 10

How is an intrauterine transfusion performed?

A) RBCs are injected into the placenta.
B) RBCs are injected into the fetal peritoneal cavity.
C) RBCs are injected into the maternal peritoneal cavity.
D) RBCs are injected into the mother and diffused through the placenta to the fetus.

Question 11

All of the following are characteristic of ABO hemolytic disease of the fetus and newborn (HDFN) except:

A) the mother is group O.
B) the mother has anti-A, B.
C) the antibody is IgM.
D) the infant has mild HDFN.

Question 12

Which red blood cell morphology is most characteristic in ABO HDFN and absent in Rh HDFN?

A) Target cells
B) Teardrop cells
C) Microspherocytes
D) Burr cells

Question 13

Active immunization induced by Rh(D) antigen can be prevented by the concurrent administration of:

A) gamma globulin.
B) Rh immunoglobulin.
C) alpha-1 protease inhibitor.
D) immune serum globulin.

Question 14

Why is the immediate spin eliminated in the prenatal antibody screen?

A) To reduce the detection of auto-antibodies
B) To reduce the detection of IgG antibodies
C) To reduce the detection of IgM antibodies
D) None of the above

Question 15

All of the following are goals of an exchange transfusion except:

A) to remove high levels of unconjugated bilirubin.
B) to correct anemia.
C) to remove high levels of conjugated bilirubin.
D) to remove high levels of maternal antibody.

Question 16

Which of the following reagents can be used to determine the immunoglobulin class of anti-M?

A) PEG
B) Chloroquine
C) 2-mercaptoethanol
D) Ficin

Question 17

Why is suppression of erythropoiesis an advantage of exchange transfusions?

A) Reduces the production of compatible RBCs
B) Reduces the production of incompatible RBCs
C) Decreases the risk of iron overload
D) Clears nucleated RBCs from circulation

Question 18

Immunization of the mother can be caused by as little as ___________D-positive fetal cells.

A) 10 mL
B) 1 mL
C) 50 mL
D) 20 mL

Question 19

A 300-µg dose of Rh-immune globulin contains sufficient anti-D to protect against how much whole blood?

A) 15 mL
B) 30 mL
C) 50 mL
D) 100 mL

Question 20

Why is reverse grouping omitted in neonate ABO grouping?

A) Maternal ABO antibody is identical to newborn ABO antibody
B) Maternal antibodies mask the ABO antibodies of the neonate
C) Newborns do not produce isoagglutinins of their own
D) None of the above

Question 21

What immunoglobulin is capable of crossing the placenta?

A) IgG
B) IgM
C) IgA
D) All of the above

Question 22

Which of the following red blood cells is appropriate for neonatal transfusions?

A) Group A, CMV-negative
B) Group AB, CMV-negative
C) Group O, CMV+
D) Group O, CMV-negative

Question 23

The most important serologic test for the diagnosis of HDFN is the___________ with anti-IgG reagents.

A) elution
B) IAT
C) DAT
D) fetal screen

Question 24

What life-threatening disorder is characterized by a severe anemia, effusions, and ascites from hepatomegaly and splenomegaly?

A) Thalassemia
B) Sickle cell anemia
C) Hereditary persistence of fetal hemoglobin
D) Hydrops fetalis

Question 25

Which of the following assays is used to calculate the amount of fetomaternal hemorrhage in a postpartum specimen?

A) Antibody specimen
B) Kleihauer-Betke test
C) Rosette test
D) Solid-phase adherence test

Question 26

The D-positive fetal cells in Rh-HDN are___________ .

A) homozygous
B) heterozygous
C) amorphic
D) homologous

Question 27

In order for the mother to be considered for Rh-immune globulin, her Rh type must be , and her newborn must be ___________.

A) Du-positive/Rh-positive
B) Rh-negative/Rh-positive
C) Du-negative/Du-negative
D) Rh-positive/Rh-negative

Question 28

Besides the Rh antibodies, what other red blood cell antibody is common to cause severe HDFN?

A) Anti-M
B) Anti-Le^a
C) Anti-K
D) Anti-Fy^b

Question 29

What effect does ABO incompatibility between mother and fetus have on maternal sensitization to Rh antigen?

A) The chance of maternal sensitization to Rh antigen is increased.
B) The chance of maternal sensitization to Rh antigen is decreased.
C) It has no effect.
D) None of the above

Question 30

What physiological phenomenon associates erythroblastosis fetalis with HDFN?

A) Release of nucleated red blood cells (RBC) into circulation of mother inflicted with HDFN
B) Release of mature RBCs into circulation of neonate inflicted with HDFN
C) Release of nucleated RBCs into circulation of neonate inflicted with HDFN
D) None of the above

Question 31

In the event of a clinically significant antibody found in the mother's serum, which of the following must be performed to determine its concentration?

A) Fetal screen
B) Antibody screen
C) Antibody titer
D) Elution

Question 32

Which of the following antibodies have not been known to cause HDFN?

A) Anti-C
B) Anti-S
C) Anti-D
D) Anti-Le^a

Question 33

What is the most common clinical manifestation of ABO HDFN?

A) Severe anemia
B) Hyperbilirubinemia
C) Hyperkalemia
D) Hypotension

Question 34

Why is the Rh-positive firstborn of an Rh-negative mother unaffected by Rh hemolytic disease of the fetus and newborn (Rh HDFN)?

A) The plasma volume of the mother is tripled during the first pregnancy which dilutes anti-D.
B) The titer of anti-D is too low to cause destruction of fetal antigens.
C) The mother has not been immunized to the D antigen before placental separation.
D) None of the above

Question 35

All of the following are true regarding antibody titration of maternal IgG antibodies except:

A) the method must include the indirect antiglobulin test.
B) the difference of two or more dilutions between titrations is considered significant.
C) red blood cells should consist of the same genotype for each titration.
D) the first serum specimen should be run in parallel with all subsequent titrations.

Question 36

The laboratory is presented with a case of HDFN due to ABO incompatibility. The mother is Group O and the infant is Group B. The most appropriate type of blood to use for an exchange transfusion for this infant is:

A) A
B) B
C) O
D) AB

Question 37

What is the physiological path of indirect bilirubin produced as a result of red blood cell destruction in HDFN?

A) Indirect bilirubin is transported across the placenta and excreted via maternal kidneys.
B) Indirect bilirubin is conjugated in the fetal liver to direct bilirubin.
C) Indirect bilirubin crosses the placenta and is conjugated in the maternal liver to direct bilirubin.
D) None of the above

Question 38

The results of a Kleihauer-Betke stain indicate a fetomaternal bleed of 40 ml of whole blood. How many vials of Rh-immune globulin would be required?

A) 1
B) 2
C) 3
D) 4

Question 39

What is the cause of HDFN?

A) Destruction of the mother's RBCs by autoantibody
B) Destruction of the fetus's RBCs by antibody produced by the mother
C) Destruction of the fetus's RBCs by autoantibody
D) Destruction of the mother's RBCs by antibody produced by the fetus

Question 40

In which type of HDFN is the firstborn affected?

A) ABO
B) Rh
C) Lewis
D) P

Question 41

How are units for exchange transfusion prepared?

A) Group O red blood cells and group O plasma
B) Group O red blood cells and group A plasma
C) Group O red blood cells and group AB plasma
D) Group O red blood cells and group B plasma

Question 42

Blood transfusions to the fetus and premature infants should be___________ to prevent graft-versus-host disease.

A) gamma irradiated
B) negative for hemoglobin S
C) less than 7 days old
D) beta irradiated

Question 43

When is the antenatal dose of Rh-immune globulin given?

A) 20 weeks
B) 13 weeks
C) 28 weeks
D) 36 weeks

Question 44

Which prenatal serologic tests are recommended during the first trimester?

A) ABO
B) Rh
C) Antibody screen
D) All of the above

Question 45

Rh-immune globulin should be given within how many hours after delivery?

A) 24
B) 48
C) 36
D) 72

Question 46

All Rh-negative recipients who are transfused with as little as 1 mL of Rh-positive cells will develop anti-D.

Question 47

Cannulation of the umbilical vein under ultrasound guidance is known as:

A) cordocentesis.
B) amniocentesis.
C) apheresis.
D) pericardiocentesis.

Question 48

The antibody titer of maternal antibody is directly proportional to severity of HDFN.

Question 49

Anti-D in the serum of a third trimester pregnant woman with a titer of 16 is indicative of:

A) Rh-immune globulin.
B) active immunization.
C) passive immunization.
D) none of the above.

Question 50

Why are premature newborns more likely to require exchange transfusions than full-term infants?

A) Premature newborns are deficient in carrier protein (albumin) for bilirubin transport.
B) Premature newborns have excess indirect bilirubin due to placental transfer of maternal bilirubin.
C) Premature newborn livers are too underdeveloped to conjugate bilirubin.
D) None of the above

Question 51

What is done to prevent HDFN caused by maternal anti-Jk^a antibody formation?

A) Give Jk^a immune globulin.
B) Monitor the mother's antibody level.
C) Prevent formation of Jk^a-positive cells in the fetus.
D) No action is necessary; anti-Jk^a will not cause HDFN.

Question 52

Rh-immune globulin is of no benefit after a person has been actively immunized and formed anti-D.

Question 53

Why does the rate of RBC destruction after birth decrease in an infant diagnosed with HDFN?

A) Maternal antibody is no longer entering infant circulation via the placenta.
B) Reticuloendothelial system of the neonate reaches an equilibrium with the rate of RBC destruction.
C) The bone marrow of the neonate compensates for sequestered RBCs.
D) None of the above

Question 54

Which IgG subclass carries more potency in red blood cell hemolysis?

A) IgG₂
B) IgG₃
C) IgG₄
D) None of the above

Question 55

Which of the following mother/infant blood types would be considered at risk for ABO hemolytic disease of the fetus and newborn?

A) Mother is group O; baby is group B.
B) Mother is group O; baby is group O.
C) Mother is group AB; baby is group B.
D) Mother is group A; baby is group O.