HDFN

Question 1

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

Answer 1

HDFN

Question 2

95% of the cases of HDFN were caused by maternal antibodies directed against the

Answer 2

RhD

Question 3

The mother can be stimulated to form RBC antibodies naturally (ABO), by

Answer 3

previous pregnancy, or transfusion
(RBC alloimmunization)

Question 4

initial diagnosis of maternal RBC alloimmunization is

Answer 4

Serologic

Question 5

reported a transfusion reaction from transfusing a husband’s blood to a postpartum woman

Answer 5

1939 Levine and Stetson

Question 6

the mother had been immunized to the fa- ther’s antigen through

Answer 6

fetomaternal hemorrhage (FMH). The antigen was later identified as RhD.

Question 7

caused by the destruction of the fetal RBCs by antibodies produced by the mother.

Answer 7

HDFN

Question 8

Only antibodies of the immunoglobulin _____ class are actively transported across the placenta via Fc receptors

Answer 8

IgG

Question 9

In the case of HDFN

Answer 9

the antibodies are directed against the blood group antigens on the fetal RBCs that were inherited from the father.

Question 10

the most common cause of HDFN

Answer 10

HDFN Caused by ABO

Question 11

are present in the plasma of all individuals whose RBCs lack the corre- sponding antigen

Answer 11

isohemagglutinins / ABO Abs

Question 12

most likely to form high-titered IgG anti-ABO antibodies, ABO HDFN is nearly always limited to A or B infants of_______ with potent anti- A,B antibodies.

Answer 12

Group O mother

Question 13

mild course of ABO HDFN

Answer 13

related to the poor development of ABO antigens on fetal RBCs

Question 14

The serious conse- quences seen with other causes of HDFN, such as

Answer 14

-still birth
-hydrops fetalis
-kernicterus

Question 15

ABO HDFN causes a bilirubin peak at

Answer 15

1 to 3 days

Question 16

the leading cause of maternal alloimmunization.

Answer 16

Fetomaternal Hemorrhage

Question 17

Interventions that can increase the risk of FMH.

Answer 17

amniocentesis
chorionic villus sampling
trauma to the abdomen

Question 18

active transport of IgG begins in the

Answer 18

Second trimester

Question 19

IgG molecules are transported via the

Answer 19

Fc portion

Question 20

more efficient in RBC intravascular he- molysis than are IgG2 and IgG4

Answer 20

IgG 1 and IgG3

Question 21

common antigens in the Rh system

Answer 21

C, E, c

Question 22

is considered the most clinically significant in its ability to cause HDFN.

Answer 22

Anti-Kell

Question 23

present on immature erythroid cells in the fetal bone marrow, so severe anemia occurs not only by destruction of circulating RBCs but also by destruc- tion of precursors

Answer 23

Kell antigens

Question 24

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

Answer 24

Hemolysis

Question 25

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

Answer 25

Erythroblastosis fetalis

Question 26

the development of high-output cardiac failure with generalized edema, effusions, and ascites, a condition known as

Answer 26

Hydrops fetalis

Question 27

Hydrops fetalis can develop

Answer 27

18 to 20 weeks

Question 28

three different phases of anemia caused by HDFN

Answer 28

early (within 7 days of birth) - due to antibody- mediated hemolysis; late hemolytic anemia (2 weeks or more after birth) - due to continued hemolysis, the expanding intravascular compartment, and natural decline of hemoglobin levels; late hyporegenerative anemia - due to marrow suppression as a result of transfusions and IUT, antibody destruction of RBC precursors, and deficiency of erythropoietin

Question 29

Onset : Within 7 days of birth Mechanism : Antibody-mediated hemolysis Bilirubin : Elevated Reticulocyte count : Normal or high

Answer 29

Early-onset anemia

Question 30

Onset : >/= 2weeks Mechanism: 1. Antibody-mediated hemolysis 2. Natural decline of Hb levels 3. Expanding intravascular volume of growing infant Bilirubin : usually elevated Reticulocyte count: Normal to High

Answer 30

Late hemolytic anemia

Question 31

Onset : >/= 2 weeks Mechanism: 1. Antibody destruction of RBC precursors and RBCs 2. Marrow suppression by IUT and transfusions 3. Erythropoietin deficiency 4. Expanding intravascular volume of growing infant Bilirubin: Normal Reticulocyte count: Low or Absent

Answer 31

Late hyporegenerative anemia

Question 32

bilirubin can reach levels toxic to the infant’s brain

Answer 32

more than 18 to 20 mg/dL

Question 33

newborn develops jaundice

Answer 33

12 - 18 hours

Question 34

most important diagnostic testing HDFN cause by ABO

Answer 34

DAT on the cord or neonatal RBCs

Question 35

recommended practice is to perform in HDFN Caused by RBC Alloimmunization

Answer 35

type and antibody detection test at the first prenatal visit, preferably during the first trimester.

Question 36

must be able to detect clinically significant IgG alloantibodies that are reactive at 37°C and in the anti- globulin phase.

Answer 36

antibody detection method, or indirect antihuman globulin test (IAT)

Question 37

prenatal specimen must be typed for

Answer 37

ABO and RhD

Question 38

For tube testing, an antibody-enhancing medium can increase sensitivity of the assay.

Answer 38

polyethylene glycol (PEG) low ionic strength solution (LISS)

Question 39

The relative concentration of all antibodies capable of cross- ing the placenta and causing HDFN is determined by

Answer 39

Antibody titration

Question 40

the recommended test for RhD-positive fathers when the mother has anti-D antibody

Answer 40

zygosity genotype testing

Question 41

the clinical diagnosis of fetal anemia can be made using an ultrasound technique called *** The measurement is based on the reduced blood viscosity at lower hematocrits and resulting in faster velocity of the blood.

Answer 41

fetal middle cerebral artery peak systolic velocity (MCA-PSV)

Question 42

done to determine fetal hematocrit.

Answer 42

Cordocentesis

Question 43

umbilical vein is visualized at the level of the cord insertion into the placenta

Answer 43

high-resolution ultrasound with color Doppler enhancement of blood flow

Question 44

monitor amniotic fluid bilirubin levels has been replaced with MCA-PSV

Answer 44

Amniocentesis

Question 45

amniotic fluid is tested by a spec- trophotometric scan optical density (∆OD) at

Answer 45

450 nm

Question 46

goal of intrauterine transfusion is to

Answer 46

maintain fetal hemoglobin above 10 g/dL

Question 47

the infant’s RBCs can be heavily antibody-bound with maternal anti-D, causing a false-negative Rh type, or what has been called

Answer 47

Blocked Rh

Question 48

most important serologic test for diagnosing HDFN is the

Answer 48

DAT with anti-IgG reagent

Question 49

collection from the donor are selected to reduce the risk of hyperkalemia

Answer 49

RBCs units less than 7 to 10 days

Question 50

After a two-volume exchange transfusion

Answer 50

90% of the red blood cells have been replaced 50% of the bilirubin has been removed

Question 51

used to metabolize the unconjugated bilirubin to isomers that are less lipophilic, less toxic to the brain, and able to be excreted through urine

Answer 51

Phototherapy at 460 to 490 nm

Question 52

is used to treat hyper- bilirubinemia of the newborn caused by HDFN

Answer 52

Intravenous immune globulin (IVIG)

Question 53

The first dose of RhIG is provided at

Answer 53

28 weeks of gestation

Question 54

The second is provided at

Answer 54

After delivery

Question 55

it is recommended to give RhIG within

Answer 55

72 hours after delivery

Question 56

a maternal blood smear is treated with acid and then stained with counterstain.

Answer 56

Kleihauer-Betke test

Question 57

Fetal cells contain ______which is resistant to acid and will remain pink

Answer 57

Hgb F

Question 58

The most common genetic backgrounds that account for this serologic typing problem are called

Answer 58

weak D phenotypes