Hemolytic Disease of the Fetus and the Newborn

Destruction of the red blood cells (RBCs) of a fetus neonate by antibodies produced by the mother

Mother can be stimulated to form RBC antibodies maturally (ABO), by previous pregnancy, or transfusion (RBC alloimmunization

Hemolytic Disease of the Fetus and the Newborn

Other name for HDFN

Erythroblastosis fetalis

Phenomenon where the RBC of the fetus leaked to maternal circulation

Fetal Maternal Hemorrhage

Factors affecting Immunization and severity of HDFN

______________________ - Even only 1ml of rbc leaked to the circulation of the mother, she will definitely produce an antibody against it.

_______________________ - If the mother is healthy (immune system is very strong), then the production of antibody against the developing fetus is inevitable.

________________________ - IgG will be produced since Rh antibody is IgG in nature

________________________ - IgG subclass I and III can severely cause HDFN

_________________________ -

• Antigenic exposure – Ex. Even only 1ml of rbc leaked to the circulation of the mother, she will definitely produce an antibody against it.

• Host factors – If the mother is healthy (immune system is very strong), then the production of antibody against the developing fetus is inevitable.

• Immunoglobulin class – IgG will be produced since Rh antibody is IgG in nature

• Antibody specificity – IgG subclass I and III can severely cause HDFN

• Influence of the ABO group

3 important factors for HDFN to occur

Red cell produced by the mother must be of ________ class

The fetus must possess an antigen that is lacking in the mother (___ antigen)

The ___________ must be well developed at birth

1. The red cell antibody produced by the mother must be of IgG class

2. The fetus must possess an antigen that is lacking in the mother (D antigen)

3. The antigen must be well developed at birth

Occurs when maternal IgG attaches to specific antigens of the fetal RBCs

Hemolysis

Destruction of red cells

Anemia

• Increase production of red cells (immature)

• Compensation of the body: body will produce more rbc to compensate for the destroyed rbcs

Primarily happens in the bone marrow and hematopoietic tissues

Erythropoiesis

when spleen and liver are stressed to produce more RBCs to compensate for anemia, then this can lead to _______________ and __________________ or ________________

hepatomegaly and splenomegaly or hepatosplenomegaly.

Also known as bilirubin in the brain

Kernicterus

Swollen liver due to too much stress to hematopoietic organs in the fetus

HYDROPS FETALIS

Diagnosis includes serologic testing of the mother via:

_______ and _________ typing

Antibody ___________
Antibody ___________

Antibody ___________

• ABO, Rh Typing • Antibody screening • Antibody identification • Antibody Titration

Also known as Percutaneous Umbilical Blood Testing

Highly specialized prenatal test in which a sample of the baby’s blood is removed from the umbilical cord for testing

Cordocentesis

Sample used for testing

Amniotic fluid

Graph used to check for danger

___________ - No danger

___________ - With minimal danger

____________ - Very dangerous

Categorized as:

Zone I – No danger

Zone II – With minimal danger

Zone III – Very dangerous

Performed by accessing the fetal umbilical vein and injecting donor RBCs directly to the vein

Intrauterine Transfusion

Main goal of intrauterine transfusion is to maintain fetal hemoglobin above _______ g/dL

10g/dL

Most centers treating HDFN uses _________ for intrauterine and neonatal transfusion because it does not possess any antigens in the red cell

Group O

Donors are screened for ________________, should be negative!

Cytomegalovirus

Blood units less than __ selected for intrauterine transfusion

7 days

Procedure done to remove bilirubin from the circulation of the baby, thus preventing kernicterus

Phototherapy

Process where it competes with the mother’s antibodies for the FC receptors on the macrophages in the infant’s spleen

Intravenous Immune Globulin

The use of whole blood or equivalent to replace the neonate’s circulating blood

• Remove high levels of unconjugated bilirubin and prevent kernicterus

Exchange Transfusion

This is given to prevent immunization to D antigen as it attaches to the fetal Rh-ppositive RBCs in the maternal circulation

RhIG (Rhogam)

Regular dose vial of Rh immunoglobulins is sufficient anti-D to protect against __mL of packed RBCs or __mL of whole blood

15mL of packed RBCs or 30mL of whole blood

A test used to detect fetomaternal hemorrhage to know if the fetal RBCs already leaked in the mother’s circulation

Rosette Testing

Quantitative analysis test should there be any Rossette formation

Kleihauer-Betke Acid Elution Test

Kleihauer-Betke Acid Elution Test (Equations)

%FRC =

FMH =

%FRC = (# of FRC / 2000 cells) (100)

FMH = %FRC x 50