HEMOLYTIC DISEASE OF THE FETUS AND

Question 1

Hemolytic Disease of the Fetus and Newborn (HDFN)

Answer 1

Destruction of fetal and neonatal RBCs by maternal antibodies

Question 2

Key factors for HDFN to occur

Answer 2

1) Maternal antibody must be IgG, 2) Fetus must possess antigen lacking in mother, 3) Antigen must be developed at birth

Question 3

ABO HDFN cause

Answer 3

Mother is Type O, fetal RBCs express B or A antigens

Question 4

Pathogenesis of ABO HDFN

Answer 4

Maternal IgG attaches to fetal RBC antigens, causing hemolysis, bilirubin increase

Question 5

Results of hemolysis in ABO HDFN

Answer 5

Anemia, increased erythropoiesis, severe anemia, hypoproteinemia, hydrops fetalis

Question 6

Hydrops fetalis condition

Answer 6

Severe anemia and hypoproteinemia leading to high-output cardiac failure and generalized edema

Question 7

Process of RBC destruction in ABO HDFN

Answer 7

Antibody-coated cells removed by spleen macrophages, increased erythropoiesis in spleen/liver

Question 8

Hepatosplenomegaly in ABO HDFN

Answer 8

Spleen and liver enlarge due to increased erythropoiesis, leading to portal hypertension

Question 9

Bilirubin metabolism in ABO HDFN

Answer 9

RBC destruction releases hemoglobin metabolized to indirect bilirubin

Question 10

Untreated ABO HDFN consequence

Answer 10

Indirect bilirubin increases, can lead to kernicterus and brain damage

Question 11

Serologic testing of the mother for HDFN

Answer 11

ABO Typing, Rh Typing, Antibody Screening and Identification, Antibody Titration

Question 12

Cordocentesis in HDFN diagnosis

Answer 12

Percutaneous umbilical cord testing to obtain a sample of the baby’s blood

Question 13

Amniocentesis in HDFN diagnosis

Answer 13

Collecting amniotic fluid for fetal lung maturity and HDFN severity assessment

Question 14

Intrauterine transfusion in HDFN management

Answer 14

Injection of donor RBCs into the fetal umbilical vein (cordocentesis)

Question 15

Preferred RBC for intrauterine transfusion in HDFN

Answer 15

Group O RBCs

Question 16

Exchange transfusion in HDFN management

Answer 16

Use of whole blood or reconstituted whole blood to replace the neonate’s circulating blood

Question 17

Intravenous immune globulin in HDFN management

Answer 17

Competes with maternal antibodies for FC receptors on macrophages in the infant’s spleen

Question 18

Management of Rh negative mother (O Rh neg) in HDFN

Answer 18

7 days prevention of hyperkalemia, maximize 2,3-DPG, use antigen-negative blood

Question 19

Prevents Anti-D formation and immunization to D antigen

Answer 19

Rhogam

Question 20

Mechanism of action of Rhogam

Answer 20

Attaches to fetal Rh-positive RBCs in the maternal circulation

Question 21

Timing of Rhogam administration

Answer 21

Given at 28th week of gestation and 72 hours after birth

Question 22

Regular-dose vial of Rhogam

Answer 22

Sufficient anti-D to protect against 15 mL of packed RBCs or 30 mL of whole blood (most common)

Question 23

Screening test for Rhogam administration

Answer 23

Rosette testing detects fetal cells in the mother

Question 24

Quantitative test for Rhogam dosage

Answer 24

Kleihauer-Betke acid test distinguishes between mother’s and infant’s cells

Question 25

Ghost cell in Kleihauer-Betke test

Answer 25

Mother’s cell

Question 26

Intact cell in Kleihauer-Betke test

Answer 26

Infant’s cell

Question 27

Formula for FMH calculation

Answer 27

% FRC = (Number of FRC / 2000) x 100%, FMH = % FRC x 50

Question 28

Indications for Rhogam

Answer 28

Rh(-) without anti-D, Rh(-) with complicated pregnancy, Rh(-) with Rh(+) baby