Hemolytic Disease of the Newborn

Question 1

In hemolytic disease of the newborn (HDN), the IgG antibodies are directed against which antigen on the fetal red blood cells?

Answer 1

Paternal

Question 2

In hemolytic disease of the newborn (HDN), once D-positive fetal cells become sensitized by maternal anti-D, what system is responsible for their destruction and removal from circulation?

Answer 2

Fetal reticuloendothelial system

Question 3

The D-positive fetal cells in Rh-HDN are _______.

Answer 3

Heterozygous

Question 4

Besides the Rh antibodies, what other red blood cell antibody is known to cause severe hemolytic disease of the newborn (HDN)?

Answer 4

anti-K

Question 5

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

Answer 5

Hydrops Fetalis

Question 6

What is the physiologic path of indirect bilirubin produced as a result of red blood cell destruction in hemolytic disease of the newborn (HDN)?

Answer 6

Indirect bilirubin crosses the placenta and is conjugated in the maternal liver to direct bilirubin

Question 7

Which of the following antibodies have not been known to cause hemolytic disease of the newborn (HDN)?

Answer 7

Anti-Lea

Question 8

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

Answer 8

Active immunization

Question 9

Anti-Kell was identified in the serum of a woman during prenatal screening. An antibody titer was determined to be 32. At 20 weeks’ gestation, a serum titer was done and determined to be 64. What procedure is now indicated based on these findings?

Answer 9

Amniocentesis

Percutaneous Umbilical Cord Sampling

Question 10

How is an intrauterine transfusion performed?

Answer 10

RBCs are injected into the peritoneal cavity

Question 11

Why is reverse grouping omitted in neonate ABO grouping?

Answer 11

Newborns do not produce isoagglutinins of their own

Question 12

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

Answer 12

Premature newborn livers are too underdeveloped to conjugate bilirubin

Question 13

How are units for exchange transfusion prepared?

Answer 13

Group O red cells and group AB plasma

Question 14

When is the antenatal dose of RhIg given?

Answer 14

28 weeks

Question 15

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

Answer 15

Fetal hemoglobin is resistant to acid and appear pink, where maternal red cells appear as ghost cells

Question 16

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

Answer 16

17

Question 17

All of the following are characteristic of ABO hemolytic disease of the newborn (HDN) except:

Answer 17

The antibody is IgM

Question 18

Which red blood cell morphology is most characteristic of in ABO hemolytic disease of the newborn (HDN), and absent in Rh HDN?

Answer 18

Microspherocytes

Question 19

In which type of hemolytic disease of the newborn (HDN), the first-born is affected?

Answer 19

ABO

Question 20

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

Answer 20

ABO
Rh
DAT