M5: Amniotic Fluid (Part 3: Tests for Fetal Distress)

Question 1

TESTS FOR FETAL DISTRESS

What are the (2) tests for fetal distress

Answer 1

1. Hemolystic disease of the fetus and newborn (HDN)
2. Neural Tube Defects (NTD)

Question 2

TESTS FOR FETAL DISTRESS

• Happens when the blood type of the mother is not compatible with the fetus
• Oldest routinely performed laboratory test on amniotic fluid
• Evaluates the severity of the fetal anemia
  produced by HDN

Answer 2

HDN

Hemolytic Disease of the Fetus and Newborn

Question 3

TESTS FOR FETAL DISTRESS

T or F

HDN’s incidence has been increasing rapidly since there are not development of methods

Answer 3

F (HDN’s incidence is decreasing rapidly due to development of method which prevent anti-Rh antibody production in post partum mothers)

Question 4

TESTS FOR FETAL DISTRESS

New methods of decreasing HDN incidence aims to prevent?

Answer 4

anti-Rh antibody production in post-partum mothers

Question 5

TESTS FOR FETAL DISTRESS

During 1st pregnancy, if the mother is Rh- and the baby is Rh+, What happens to pregnancy and placenta

Answer 5

Pregnancy is safe
Placenta is intact

safe pa pag 1st baby aw panganay momints

Question 6

TESTS FOR FETAL DISTRESS

T or F

The baby is safe as long as placenta is not destroyed

HDN

Answer 6

T

Question 7

TESTS FOR FETAL DISTRESS

occurs during gestation, delivery of the placenta, or a previous pregnancy when fetal red blood cells enter into the maternal circulation and stimulate the mother to produce antibodies to the
antigen

HDN

Answer 7

Initial exposure to foreign red cell antigens

Question 8

TESTS FOR FETAL DISTRESS

Initial exposure to foreign red cell antigens cause mother to stimulate what?

hdn

Answer 8

production of antibodies against antigen of baby

Question 9

TESTS FOR FETAL DISTRESS

Upon giving birth, the placenta?

HDN

Answer 9

detaches

point when the mother is already exposed to the Rh
antigen, thus producing Rh antibodies

Question 10

TESTS FOR FETAL DISTRESS

During 2nd pregnancy, once the body of the mother hasbeen triggered to produce Rh antibodies against D antigen,
these antibodies will?

HDN

Answer 10

attach to the fetal cells of the 2nd baby

especially when the baby is Rh+

results to anemia of baby

Question 11

TESTS FOR FETAL DISTRESS

Once antibodies are present in fetal circulation, it binds to what? leading to?

HDN

Answer 11

antibodies bind to antigen of fetal cells, leading to destruction of cells and anemia

Question 12

TESTS FOR FETAL DISTRESS

State the process of HDN or familiarize

Answer 12

1. DURING 1ST PREGNACY: baby is still safe
2. AFTER BIRTH: mother exposed to Rh antigen -> producing antibodies
3. DURING 2ND PREGNANCY: Antibodies of mother attack acells of baby leading to anemia

Question 13

TESTS FOR FETAL DISTRESS

During 1st pregnancy, After birth, During 2nd pregnancy

Fetal blood enters maternal circulation via placenta

Choose

HDN

Answer 13

During 1st pregnancy

Question 14

During 1st pregnancy, After birth, During 2nd pregnancy

IgG antibodies remain in mother’s circulation, Baby remains safe

Choose

HDN

Answer 14

During 1st pregnancy

Question 15

During 1st pregnancy, After birth, During 2nd pregnancy

Mother produces antibodies against baby rh antigen

Choose

HDN

Answer 15

After birth

Question 16

During 1st pregnancy, After birth, During 2nd pregnancy

IgG antibodies cross placenta destryong fetal rh antigen RBCs

Choose

HDN

Answer 16

During 2nd pregnancy

Question 17

TEST FOR HDN

What is the test/parameter used for detection of HDN?

Answer 17

Bilirubin

Question 18

TEST FOR HDN

(2) methods to visualize bilirubin

Answer 18

Liley Graph, Queenan curve

Question 19

TEST FOR HDN

T or F

The destruction of fetal red blood cells results in the appearance of the red blood cell degradation product, conjugated bilirubin in amniotic fluid

Answer 19

F (The destruction of fetal red blood cells results in the appearance of the red blood cell degradation product, unconjugated bilirubin in amniotic fluid)

Question 20

TEST FOR HDN

T or F

Amount of bilirubin = extent of hemolysis/danger of anemia to fetus

Answer 20

T

Question 21

TEST FOR HDN

Amniotic fluid bilirubin is measured by?

Answer 21

Spectrophotometric analysis using serial dilutions

Question 22

TEST FOR HDN

The optical density (OD) of the fluid is measured in intervals between?

Answer 22

365 and 550 nm

the readings plotted on semilogarithmic graph paper

Question 23

TEST FOR HDN

In normal fluid, OD is higest/peak and decreases at what nanometer?

Answer 23

highes peak at 365 nm
decreases linearly at 550 nm

illustrated by a straight line

Question 24

TEST FOR HDN

When bilirubin is presnet, what is the rise in OD seen?

Answer 24

450 nm

wavelength of maximum bilirubin absorption

Question 25

# TEST FOR HDN The difference between the **OD of the theoretic baseline** and the **OD at 450 nm** represents the?

Answer 25

Amniotic fluid bilirubin concentration ## Footnote difference in OD/absorbance difference at 450 nm ("A450)

Question 26

# TEST FOR HDN The theoretic baseline depends on?

Answer 26

age of gestation

Question 27

# TEST FOR HDN Difference in OD is also referred to as ?

Answer 27

Absorbance difference at 450 nm ("A450)

Question 28

# TEST FOR HDN * Difference in OD/Absorbance difference at 450 nm ("A450) is plotted on this * Determine severity of hemolytic siease * Divided into three zones | What method of detection/visualtization

Answer 28

Liley graph

Question 29

# TEST FOR HDN: BILIRUBIN plots the "A450 against gestational age and is divided into three zones that represent the extent of hemolytic severity | What method of detection/visualtization

Answer 29

Liley graph

Question 30

# TEST FOR HDN: BILIRUBIN Values falling in this zone indicate no more than a mildly affected fetus ## Footnote Liley graph: 3 zones

Answer 30

Zone I

Question 31

# TEST FOR HDN: BILIRUBIN * Values indicate moderate hemolysis and require careful monitoring * anticipating an early delivery or exchange transfusion upon delivery ## Footnote Liley graph: 3 zones

Answer 31

ZONE II

Question 32

# TEST FOR HDN: BILIRUBIN * Values indicates severe hemolysis and suggests a severely affected fetus * induction of labor or intrauterine exchange transfusion | Liley graph: 3 zones

Answer 32

ZONE III

Question 33

# TEST FOR HDN: BILIRUBIN What zone does value fall based on intervention? require careful monitoring anticipating an **early delivery** or **exchange transfusion** upon delivery ## Footnote Liley graph: 3 zones

Answer 33

Zone II

Question 34

# TEST FOR HDN: BILIRUBIN What zone does value fall based on intervention? require careful monitoring anticipating an **induced labor** or **intrauterine exchange transfusion** upon delivery ## Footnote Liley graph: 3 zones

Answer 34

Zone III

Question 35

# TEST FOR HDN: BILIRUBIN What zone does value fall based on intervention? No intervention since normal ## Footnote Liley graph: 3 zones

Answer 35

Zone I

Question 36

# TEST FOR HDN: BILIRUBIN * amniotic fluid ΔA450 values at 14 to 40 weeks’ gestation * More specific and detailed in terms of the week of gestation | What method of detection/visualtization

Answer 36

Queenan curve

Question 37

# TEST FOR HDN: BILIRUBIN If specimens are not protected from light, there will be markedly decreased values within time frame of? | Queenan curve

Answer 37

as little as 30 minutes of exposure to light

Question 38

# TESTS FOR FETAL DISTRESS Increased levels of alpha-fetoprotein (AFP)

Answer 38

Neural Tube Defects

Question 39

# TESTS FOR FETAL DISTRESS * is the major protein produced by the fetal liver during early gestation (prior to 18 weeks) * found in the maternal serum due to the combined fetal-maternal circulations and in the amniotic fluid from diffusion and excretion of fetal urine | NTD

Answer 39

AFP (Alpha-fetoprotein)

Question 40

# NEURAL TUBE DEFECTS Increased levels of AFP are found in? | (2)

Answer 40

Maternal serum and Amniotic fluid | primarily maternal serum ## Footnote when the skin fails to close over the neural tissue

Question 41

# NEURAL TUBE DEFECTS Normal value for AFP?

Answer 41

<2.0 MoM

Question 42

# NEURAL TUBE DEFECTS are based on the **week of gestational age**, as the fetus produces maximal AFP between 12 and 15 weeks’ gestation after which levels in amniotic fluid begin to decline

Answer 42

Normal values

Question 43

# NEURAL TUBE DEFECTS maximal AFP produced by fetus is during when?

Answer 43

between 12 and 15 weeks’ gestation | after which levels in amniotic fluid begin to decline

Question 44

# NEURAL TUBE DEFECTS Maternal serum and Amniotic fluid are reported in terms of?

Answer 44

multiples of the median (MoM)

Question 45

# NEURAL TUBE DEFECTS is the laboratory’s reference level for a given week of gestation

Answer 45

Median

Question 46

# NEURAL TUBE DEFECTS T or F A value two times the median value is considered abnormal for both maternal serum and amniotic fluid

Answer 46

T

Question 47

# NEURAL TUBE DEFECTS Increased levels of alpha-fetoprotein (AFP) in maternal and amniotic fluid indicates NTD specifically what (2) neural tube defects

Answer 47

Anencephaly and Spina bifida

Question 48

# NEURAL TUBE DEFECTS when a baby's spine and spinal cord does not develop properly in the womb, causing a gap in the spine

Answer 48

Spina bifida

Question 49

# NEURAL TUBE DEFECTS a fatal condition where a baby is born without parts of the brain and skull.

Answer 49

Anencephaly

Question 50

# NEURAL TUBE DEFECTS NTD are detected by what (3) methods?

Answer 50

* Maternal serum alpha-fetoprotein (MSAFP) blood test * High-resolution ultrasound * Amniocentesis | Mom, High, Ako

Question 51

# NEURAL TUBE DEFECTS * Measurement followed after elevated amniotic fluid AFP levels * More specific for neural tube disorders than AFP (provided it is not performed on a bloody specimen)

Answer 51

Amniotic Acetylcholinesterase (AChE)

Question 52

T or F Amniotic acetylcholinesterase (AChE) is more specific than aFP, provided it is not perfromed on bloody specimen since blood has AChE

Answer 52

T