FETAL DISORDERS

Question 1

FETAL DISORDERS etiology

Answer 1

• May be ACQUIRED - Alloimmunization
• May be GENETIC - Congenital Adrenal Hyperplasia, 4alpha Thalassemia
• May be SPORADIC - Structural abnormalities

Question 2

One of the most frequent causes of

fetal anemia

Answer 2

RED CELL ALLOIMMUNIZATION

Question 3

Results from transplacental passage of
maternal antibodies that destroy fetal
red cells

Answer 3

RED CELL ALLOIMMUNIZATION

Question 4

RED CELL ALLOIMMUNIZATION will lead to

Answer 4

overproduction of immature fetal and neonatal red cells ERYTHROBLASTOSIS FETALIS)

Question 5

RED CELL ALLOIMMUNIZATION detected by

Answer 5

Blood type and Antibody screening during 1 st

PNCU

Question 6

RED CELL ALLOIMMUNIZATION dx test

Answer 6

• Unbound antibodies detected by INDIRECT COOMB’S TEST
• IgG antibodies are assessed since these are the ones that cross the placenta
• Critical titer for anti D ≥1:16 can cause significant fetal anemia

Question 7

D negative mother and D positive fetus

Answer 7

increased chance of alloimmunization

Question 8

• Absence of D Antigen

- Sensitized after single exposure of 0.1 mL of fetal RBCs

Answer 8

D NEGATIVITY

Question 9

D Sensitization also may occur following

Answer 9

• first trimester pregnancy complications
• prenatal diagnostic procedures
• maternal trauma

Question 10

Five Red Cell Antigens

Answer 10

c, C, D, E, e

Question 11

have lower immunogenicity but can cause

hemolytic disease

Answer 11

C, c, E and e Antigens

Question 12

CDE most common blood group incompatibility

Answer 12

Anti E alloimmunization

Question 13

greater need for fetal or neonatal transfusion

Answer 13

Anti c alloimmunzation

Question 14

current pregnancy is jeopardized by maternal antibodies that were initially provoked by his or her grandmother’s erythrocytes

Answer 14

Grandmother effect

Question 15

Most common cause of hemolytic disease with A and B Blood group antigens

Answer 15

ABO BLOOD GROUP INCOMPATIBILITY

Question 16

ABO vs CDE Incompatibility

Answer 16

• ABO incompatibility seen in first born
• ABO rarely become more severe in successive pregnancy
• ABO more of pediatric concern
• Most ABO Antibodies don’t cross the placenta (IgM)
• Fetal cells are less immunogenic due to less A and B antigenic sites

Question 17

ALLOIMMUNIZED PREGNANCY will develop in what

Answer 17

• Mild to moderate hemolytic anemia

- Hydrops fetalis

Question 18

MANAGEMENT OF ALLOIMMUNIZED PREGNANCY

Answer 18

• Monitoring of titer, repeated every 4 weeks if below the critical level
• If within critical level , further evaluation should be done and no benefit with repeating the titer level

Question 19

25% to 30% D alloimmunized will develop

Answer 19

mild to moderate hemolytic anemia

Question 20

25% of alloimmunized pregnancy will develop

Answer 20

hydrops fetalis

Question 21

MANAGEMENT: DETERMINE FETAL RISK

Answer 21

-40% risk for D Negative mother to have D Negative fetus
-Amnestic Response - Patient is sensitized from previous exposure but titer may be elevated with
current pregnancy even if the fetus is D Negative
-Initial evaluation
*Determine paternal erythrocyte antigen status
*Paternal zygosity
*Fetal genotype

Question 22

MANAGEMENT: ALLOIMMUNIZED PREGNANCY

Answer 22

-Individualized
-Monitoring
*Accurate fetal aging is critical
*Aging when anemia develops
*Maternal antibody titer surveillance
*Sonographic monitoring of Middle Cerebral Artery (MCA) peak systolic
velocity
*Amniotic fluid bilirubin studies
*Fetal blood sampling and blood transfusion

Question 23

PREVENTION OF ANTI D ALLOIMMUNIZATION

Answer 23

-Administration of anti D immune globulin
at 28 weeks gestation
-Routine postpartum administration within 72 hours of delivery lowers the alloimmunization by 90%
-Anti D Immune globulin
*Rosette test: positive
*Kleihauer Betke Test: (+) fetal cells in maternal blood

Question 24

• Approximately, 2/3 provoke an Antigen-Antibody reaction

- Incidence directly proportional to AOG

Answer 24

FETAL HEMORRHAGE INCIDENCE

Question 25

FETAL HEMORRHAGE causes

Answer 25

- Placenta previa - Placental chorioangioma - Vasa previa

Question 26

FETAL HEMORRHAGE ssx

Answer 26

Decreased fetal movement

Question 27

FETAL HEMORRHAGE seen in diagnostics

Answer 27

- Sinusoidal fetal heart rate pattern | - Elevated MCA Peak Systolic Velocity on Ultrasound

Question 28

No significant effect on fetal heart rate unless fetus is moribund

Answer 28

CHRONIC ANEMIA

Question 29

- Poorly tolerated by the fetus | - May cause profound neurologic impairment from cerebralhypoperfusion, ischemia and infarction

Answer 29

ACUTE ANEMIA

Question 30

*Most commonly used quantitative test for fetal red cells in the maternal circulation *Hemoglobin F is resistant to acid elution (darker) * “Ghosts” --> maternal RBCs

Answer 30

Kleihauer-Betke Test (Acid Elution)

Question 31

resistant to acid elution (darker)

Answer 31

Hemoglobin F

Question 32

Hemorrhage Quantification for fetal hemorrhage

Answer 32

1. Computation of FBV from result of KB test 2. Flow Cytometry

Question 33

- Uses monoclonal antibodies to hemoglobin F or D antigen - Followed by quantification of fluorescence - More sensitive and More accurate - Unaffected by maternal blood cells

Answer 33

Flow cytometry

Question 34

-Most common cause of Severe Thrombocytopenia -also known as FNAIT (Fetal and Neonatal Alloimmune Thrombocytopenia) or NAIT (Neonatal Alloimmune Thrombocytopenia)

Answer 34

Alloimmune Thrombocytopenia (AIT)

Question 35

- Caused by maternal alloimmunization to paternally inherited fetal platelet antigens - Maternal antiplatelet antigens cross the placenta - Maternal platelet alloimmunization is usually against human platelet antigen 1a (HPA 1a)

Answer 35

FETAL AND NEONATAL ALLOIMMUNE THROMBOCYTOPENIA (FNAIT)

Question 36

FETAL AND NEONATAL ALLOIMMUNE | THROMBOCYTOPENIA (FNAIT) diagnosis

Answer 36

Upon delivery of a neonate, when there is severe and unexplainable thrombocytopenia from a mother with normal platelet count

Question 37

FETAL AND NEONATAL ALLOIMMUNE | THROMBOCYTOPENIA (FNAIT) diagnosis

Answer 37

- Intravenous Immune globulin (IVIG) and Prednisone: * Increases Platelet count by 50,000 u/L or 80% increase if used in combination * Side effects of IVIG : fever, headache, myalgia, nausea/vomiting and rash

Question 38

FETAL AND NEONATAL ALLOIMMUNE | THROMBOCYTOPENIA (FNAIT) mode of delivery

Answer 38

* CS for term or near term | * Non instrumental vaginal delivery if Platelet count is >100,000/ uL

Question 39

IMMUNE THROMBOCYTOPENIA pathogenesis

Answer 39

- Antiplatelet IgG antibodies that attack platelet glycoproteins - Crosses the placenta and causes fetal thrombocytopenia (mild)

Question 40

IMMUNE THROMBOCYTOPENIA also known as

Answer 40

Immune Thrombocytopenic Purpura (ITP)

Question 41

IMMUNE THROMBOCYTOPENIA mode of delivery

Answer 41

- Vaginal | - CS for Obstetric indications

Question 42

- Excessive accumulation of serous fluid - Edema of the fetus * Associated with placentomegaly and hydramnios * Skin thickness >5 mm and placental thickness of at least 4 cm (2nd trimester) and 6 cm (3rd trimester)

Answer 42

HYDROPS FETALIS

Question 43

prenatal diagnosis of hydrops fetalis

Answer 43

Ultrasound - 2 or more fetal effusions * Pleural * Pericardial * Ascites - 1 effusion plus Anasarca

Question 44

HYDROPS FETALIS: IMMUNE TYPE results from

Answer 44

Transplacental passage of maternal antibodies that destroy fetal red cells

Question 45

HYDROPS FETALIS: IMMUNE TYPE Associated with

Answer 45

Red Cell Alloimmunization

Question 46

Incidence declined dramatically due to * Anti D Immune globulin administration * MCA Doppler Studies for early detection * Fetal Blood transfusion

Answer 46

HYDROPS FETALIS: IMMUNE TYPE

Question 47

HYDROPS FETALIS: IMMUNE TYPE Pathophysiology

Answer 47

- Decreased colloid oncotic pressure - Increased hydrostatic pressure - Enhanced vascular permeability

Question 48

HYDROPS FETALIS: IMMUNE TYPE complications

Answer 48

-anemia --> stimulates marrow erythroid hyperplasia and extramedullary hematopoiesis in the spleen and liver *usually severe (Hgb < 5g/dL) -Tissue hypoxia --> may increase capillary permeability causing fluid accumulation in the thorax, abdominal cavity and subcutaneous tissue

Question 49

- 90% of cases of hydrops fetalis - Etiology is identified depending of age of gestation - Prenatally (Aneuploidy, Cardiovascular abnormalities, Infections (Parvovirus B19) - Prognosis depends on etiology

Answer 49

HYDROPS FETALIS: NON IMMUNE TYPE

Question 50

Causes of fetal hydrops

Answer 50

``` Fetal anemia Fetal arrhythmia Structural abnormality Aneuploidy Placental abnormality Monochorionic twinning complications ```

Question 51

fetal hydrops

Answer 51

-Initial Evaluation *Indirect Coomb’s test for alloimmunization *Targeted sonographic fetal and placental evaluation --Detailed anatomic survey --MCA Peak Systolic Velocity --Fetal echocardiogram *Amniocentesis and TORCH evaluation *Kleihauer Betke test *Thalassemia work up

Question 52

- Association of fetal hydrops and development of maternal edema - “Triple Edema”: fetus, mother and placenta all edematous - Form of Severe preeclampsia * 90% edema * 60% hypertension * 40% proteinuria * 20% elevated liver enzymes * 15% headache and visual disturbance

Answer 52

MIRROR SYNDROME

Question 53

Triple edema

Answer 53

edematous: - fetus - mother - placenta

Question 54

Management of mirror syndrome

Answer 54

Prompt Delivery and Resolution of maternal edema