Hemolytic Disease of the Fetus and Newborn Flashcards
Prenatal testing includes:
pregnancy and transfusion history, ABO/Rh (with weak D) type, and antibody screen
Prenatal monitoring is done if the mother has what test results?
a positive antibody screen and the antibodies are clinically significant
How is prenatal monitoring done?
monitoring antibody titers and fetal distress
What test is performed to detect fetal cells in the mother?
Kleihauer-Betke Acid Elution
At what pH is the acid buffer in the Kleihauer-Betke test?
3.3
Which cells are not soluble in the acid buffer used for the Kleihauer-Betke test?
fetal cells
The selection of blood for an fetus/newborn exchange transfusion must include which 4 requirements?
Irradiated, CMV negative, No more than 5-7 days old, negative for Hgb S
What blood type is most commonly used in exchange transfusions?
Type O
If the mother and infant are both type O, what type can the donor be?
Type O
If the Mother is type A or B and the infant is Type O, what Type must the donor be?
Type O
For exchange transfusions, the donor blood must be compatible with who?
both the mother and the fetus/infant
If the mother is Type O and the Infant is Type A, what type must the donor be?
O
If the Mother is type B and the infant is Type A, what type must the donor be?
Type O
If the Mother is type A and the infant is type A, what type must the donor be?
A or O
If the mother is Type AB and the infant is Type A what type must the donor blood be?
A or O
If the mother is type O and the infant is type B, the donor blood needs to be Type…
O
If the mother is type A and the infant is type B, the donor unit needs to be type…
O
If the mother is Type B or AB and the infant is type B, what type must the donor blood be?
B or O
If the mother is type A and the infant is type AB, what type must the donor blood be?
Type A or O
If the mother is type B and the infant is type AB, what type must the donor blood be?
B or O
If the mother is type AB and the infant type is AB, what type of blood can be donated?
AB, A, B, or O
What is Hemolytic Disease of the Fetus and Newborn?
The destruction of fetus/newborn RBCs from maternal antibodies crossing the placenta
What are two other names for HDFN?
Erythroblastosis fetalis OR Hydrops fetalis
Other than anti-D, what are the other 5 most common and significant antibodies that can cause HDFN?
anti-K, -E, -c, -C, and -Fy(a)
Why is ABO HDFN considered “protective” against other forms of HDFN?
The RBCs are being destroyed by ABO antibodies before the mom can be sensitized to the other antigens of the fetal cells.
What is RhIg?
a form of passive anti-D that binds and destroys fetal RBCs circulating in the mom before the mom can be sensitized and form her own anti-D
What would cause a positive DAT on a cordocentesis sample and why is that the only answer?
Maternal antibodies cause the positive DAT because fetus and neonates don’t have formed antibodies to cause the DAT to be positive.
If a DAT is positive, what procedure is done next?
elution
Fetal DNA testing can be done as early as how many weeks gestation?
10 to 12 weeks
The relative concentration of all antibodies capable of crossing the placenta and causing HDFN is determined by…
antibody titration
Antibody titration method must include which testing phase and reagent?
indirect antiglobulin phase with monospecific anti-IgG