HEMOLYTIC DISEASE OF THE NEWBORN

Question 1

Refers to the destruction of the red blood cells of a fetus and neonate by antibodies produced by the mother; could be due to ABO incompatibility or RBC alloimmunization

Answer 1

Hemolytic Disease of the Newborn

Question 2

Destruction of fetal RBCs and the resulting anemia stimulate the fetal bone marrow to produce RBCs at an accelerated rate

Answer 2

Erythroblastosis fetalis

Question 3

Severe anemia and hypoproteinemia caused by decreased hepatic production of plasma proteins leading to cardiac failure, generalized edema, effusions, and ascites

Answer 3

Hydrops fetalis

Question 4

After birth, the immature infant liver cannot yet metabolize bilirubin efficiently, and this leads to the accumulation of unconjugated bilirubin and neonatal jaundice

Answer 4

Hyperbilirubinemia

Question 5

Seepage of fetal RBC going to maternal blood circulation

Answer 5

Fetomaternal hemorrhage (FMH)

Question 6

Important tests done for evaluation of newborns:

Answer 6

1. ABO, Rh typing
2. DAT (if + for HDN)
3. AntibodyTiter

Question 7

Reduces risk of maternal alloimmunization due to D antigen (less than 0.1% chance); RhIG attaches to fetal Rh-positive RBCs in maternal circulation, blocking immunization and subsequent production of anti-D resulting to prevention of producing anti-D

Answer 7

Rh Immune Globulin/ RhIG (RhoGAM)

Question 8

Storage and shelf-life of RhIG (RhoGAM):

Answer 8

1-6C; 2 years

Question 9

RhIG should be given to RhD-negative mothers
- Antenatal:
- Postpartum:

Answer 9

RhIG should be given to RhD-negative mothers
- Antenatal: 28 weeks gestation (before giving birth; 7 month pregnancy)
- Postpartum: within 72 hours after child delivery

Question 10

U.S. regular dose vial (300 ug) protects against ___ mL of whole blood or ___ mL of PRBCs

Answer 10

30 mL of whole blood
15 mL PRBCs

Question 11

Purpose of Rosette test:

Answer 11

Screening test for FMH

Question 12

Purpose of Kleihauer-Betke:

Answer 12

Quantitates volume of FMH

Question 13

Specimen used for Rosette test:

Answer 13

Maternal red cells

Question 14

Specimen used for Kleihauer-Betke:

Answer 14

Maternal blood smear

Question 15

Reagent used in Rosette test:

Answer 15

Anti-D (IgM/IgD)
Ficin-treated R2R2 cells

Question 16

Reagents used in Kleihauer-Betke:

Answer 16

Weak citric acid
Wright’s stain

Question 17

Kleihauer-Betke test result

Pink cells -
Ghost cells -

Answer 17

Kleihauer-Betke test result

Pink cells - Fetal RBCs (Hb-F)
Ghost cells - Maternal RBCs (Hb A)

Question 18

VOFMH (Volume of Fetomaternal Hemorrhage) formula:

Answer 18

% of Fetal cells x 50 (constant) = VOFMH in mL

then

VOFMH/30 = number of required vials of RhIg

Question 19

Primarily used to remove high levels of bilirubin and prevent kernicterus; also used for removal of maternal antibodies and sensitized RBCs

Answer 19

Exchange transfusion

note: exchange transfusion is rare for ABO, and common in Rh

Question 20

Blood transfusion using the umbilical vein in the placenta; preferred is type O Rh D-negative irradiated RBCs, and less than 7 days old from collection

Answer 20

Intrauterine transfusion