Isoimmunization

Question 1

WHat is the formation of maternal antibodies?

Answer 1

Isoimmunization

Question 2

What is the most common antigen involved in sioimmunization?

Answer 2

Rh specifically the D antigen

Question 3

Patients with the D antigen are what?

Answer 3

Rh D-positive

Question 4

When does isoimmunization occur?

Answer 4

Rh D-negative woman is pregnant with a fetus that is Rh D-positive. Can cause an antibody response against fetal RBCs

Question 5

What characterizes isoimmunization?

Answer 5

hemolysis
bilirubin release
anemia

Question 6

How much blood is sufficient to cause isoimmunization?

Answer 6

Less than 0.1 mL of Rh d-positive blood

Question 7

Is IgG the first or secondary antibody response?

Answer 7

Secondary

Question 8

What is the combination of fluid accumulation in at least 2 extravascular compartments called?

Answer 8

Hydrop fetalis

Question 9

How do you diagnose isoimmunization?

Answer 9

Test for antibodies

The higher the titer, the more significant the antibody response

Question 10

What do you do if fetal anemia or hydrophic changes are found?

Answer 10

Cordocentesis of percutaneous umbilical blood sampling (PUBS) to measure direct fetal HCT

Question 11

How do you evaluate fetal anemia?

Answer 11

Amniotic fluid assessment of bilirubin levels
Loo for hydropic changes
Measure blood viscosity of MCA (will have increased flow)

Question 12

How do you manage isoimmunity?

Answer 12

Direct transfusion under US guidance of antigen-negative rbc’s to the fetus (want HCT >30%)

Question 13

What can you give for prevention of isoimmunization?

Answer 13

GIve RhoGAM or Rhophylac to all RhD-neg women at 28 weeks and w/i 72 hours of delivery

Question 14

What is a test that can identify fetal erythrocytes in materal circulation and the appropriate dose of Rh immunoglobulin to be administered.

Answer 14

Kelihauer-Betke test

Question 15

WHat is a test that can be used to determine if the patient has received sufficient antibody.

Answer 15

Indirect Coombs test (positive means the dosage was adequate)

Question 16

What is the Kell Antigen?

Answer 16

Results from a blood transfusion. Unique anemia results from destruction and suppression of hematopoietic precursor cells and hemolysis is limited

Question 17

What is where there is maternal-fetal incompatibility usually associated with mild fetal anemia and newborn hyperbilirubinemia. Not associated w/ severe fetal disease.

Answer 17

ABO hemolytic disease

Question 18

What is the proliferating tropoblast that gives rise to a layer of extraembryonic mesoderm on its intersurface (outer)

Answer 18

Chorion

Question 19

What is the inner sac that develops at the dorsal surface of the embryonic dis forming a transparent sac that fills amniotic fluid.

Answer 19

Amnion

Question 20

What is where each fetus is surrounded by an amnion and a chorion?

Answer 20

Diamnionic/ dichoronic

Question 21

What is where each fetus is surrounded by an amnion, but a single chorion?

Answer 21

Diamnionic/ monochoroionic

Question 22

What is where twins will share a common sac as the amnion and chorion have already developed?

Answer 22

monoamnionic/ monochorionic

Question 23

What is where there is arterial-venous anastomoses that forms between the fetus resulting in blood flow from one to another?

Answer 23

Twin-twin transfusion syndrome

Question 24

What is the name for the twin that has impaired growth, anemia, hypovolemia, oligohydramnios (from decreased urine output)?

Answer 24

Donor twin

Question 25

What is the twin that may have hypervolemia, HTN, polycythemia, CHF, can have polyhydramnios (due to increased urine output)

Answer 25

Recipient twin

Question 26

What is when fetal weight is less than 10th percentile for gestational age?

Answer 26

IUGR (intrauterine growth restriction)

Question 27

What is later onset IUGR usually realted to?

Answer 27

Decreased placental function and nutrient transport

Question 28

WHat usually causes IUGR?

Answer 28

placenta growth early and rapidly compared to the fetus; has large surface area

Question 29

Which type of IUGR is more commonly associated w/ heritable factors, immunologic abnormalities, chronic maternal disease, fetal infection, multiple pregnancies?

Answer 29

Early-onset IUGR

Question 30

What constitutes a IUGR diagnosis?

Answer 30

A discrepancy of more than 2 cm | DO an ultrasound for biparietal diameter (BPD), head circumference (HC), femur length, abdominal circumference (AC)

Question 31

What syndrome is from the fetus' attempt to compensate for poor placenta oxygen transfer by increasing the HCT o more than 5% resultin gin marked polycytehmia. Can lead to thrombosis, heart failure, hyperbilirubinemia.

Answer 31

Hyperviscosity syndrome

Question 32

What is where the infant weighs 4000-4500 grams or greater.

Answer 32

Fetal macrosomia

Question 33

What is an LGA infant?

Answer 33

Large for gestational age. >90%

Question 34

What is the best tool to r/o macrosomia?

Answer 34

Ultrasound