15 AMNIOTIC FLUID

Question 1

Which of the following is not a function of amniotic fluid?
A. Allows movement of the fetus
B. Allows exchange of carbon dioxide and oxygen
C. Protects the fetus from extreme temperature changes
D. Acts as a protective cushion for the fetus

Answer 1

B. Allows exchange of carbon dioxide and oxygen

Question 2

What is the primary cause of the normal increase in amniotic fluid as a pregnancy progresses?
A. Fetal cell metabolism
B. Fetal swallowing
C. Fetal urine
D. Transfer of water across the placenta

Answer 2

C. Fetal urine

Question 3

Which of the following is not a reason for decreased amounts of amniotic fluid?
A. Fetal failure to begin swallowing
B. Increased fetal swallowing
C. Membrane leakage
D. Urinary tract defects

Answer 3

A. Fetal failure to begin swallowing

Question 4

Why might a creatinine level be requested on an amniotic fluid?
A. Detect oligohydramnios
B. Detect polyhydramnios
C. Differentiate amniotic fluid from maternal urine
D. Evaluate lung maturity

Answer 4

C. Differentiate amniotic fluid from maternal urine

Question 5

Amniotic fluid specimens are placed in amber-colored tubes before sending them to the laboratory to prevent the destruction of:
A. Alpha-fetoprotein
B. Bilirubin
C. Cells for cytogenetics
D. Lecithin

Answer 5

B. Bilirubin

Question 6

How are specimens for FLM testing delivered to and stored in the laboratory?
A. Delivered on ice and refrigerated
B. Immediately centrifuged
C. Kept at room temperature
D. Delivered in a vacuum tube

Answer 6

A. Delivered on ice and refrigerated

Question 7

Why are amniotic specimens for cytogenetic analysis
incubated at 37°C before analysis?
A. To detect the presence of meconium
B. To differentiate amniotic fluid from urine
C. To prevent photo-oxidation of bilirubin to biliverdin
D. To prolong fetal cell viability and integrity

Answer 7

D. To prolong fetal cell viability and integrity

Question 8

Match the following colors in amniotic fluid with their significance.

COLORLESS

A. Fetal death
B. Normal
C. Presence of bilirubin
D. Presence of meconium

Answer 8

B. Normal

Question 9

Match the following colors in amniotic fluid with their significance.

DARK GREEN

A. Fetal death
B. Normal
C. Presence of bilirubin
D. Presence of meconium

Answer 9

D. Presence of meconium

Question 10

Match the following colors in amniotic fluid with their significance.

RED-BROWN

A. Fetal death
B. Normal
C. Presence of bilirubin
D. Presence of meconium

Answer 10

A. Fetal death

Question 11

Match the following colors in amniotic fluid with their significance.

YELLOW

A. Fetal death
B. Normal
C. Presence of bilirubin
D. Presence of meconium

Answer 11

C. Presence of bilirubin

Question 12

A significant rise in the OD of amniotic fluid at 450 nm indicates the presence of which analyte?
A. Bilirubin
B. Lecithin
C. Oxyhemoglobin
D. Sphingomyelin

Answer 12

A. Bilirubin

Question 13

Plotting the amniotic fluid OD on a Liley graph represents the severity of hemolytic disease of the fetus and newborn.
A value that is plotted in zone II indicates what condition of the fetus?
A. No hemolysis
B. Mildly affected fetus
C. Moderately affected fetus that requires close monitoring
D. Severely affected fetus that requires intervention

Answer 13

C. Moderately affected fetus that requires close monitoring

Question 14

The presence of a fetal neural tube disorder may be detected by:
A. Increased amniotic fluid bilirubin
B. Increased maternal serum alpha-fetoprotein
C. Decreased amniotic fluid phosphatidyl glycerol
D. Decreased maternal serum acetylcholinesterase

Answer 14

B. Increased maternal serum alpha-fetoprotein

Question 15

True or False: An AFP MoM value greater than two times the median value is considered an indication of a neural
tube disorder.

Answer 15

True

Question 16

When severe HDFN is present, which of the following tests on the amniotic fluid would the physician not order
to determine whether the fetal lungs are mature enough
to withstand a premature delivery?
A. AFP levels
B. Foam stability index
C. Lecithin/sphingomyelin ratio
D. Phosphatidyl glycerol detection

Answer 16

A. AFP levels

Question 17

True or False: Before 35 weeks’ gestation, the normal L/S ratio is less than 1.6.

Answer 17

True

Question 18

When performing an L/S ratio by thin-layer
chromatography, a mature fetal lung will show:
A. Sphingomyelin twice as concentrated as lecithin
B. No sphingomyelin
C. Lecithin twice as concentrated as sphingomyelin
D. Equal concentrations of lecithin and sphingomyelin

Answer 18

C. Lecithin twice as concentrated as sphingomyelin

Question 19

True or False: Phosphatidyl glycerol is present with an
L/S ratio of 1.1.

Answer 19

True

Question 20

A rapid immunologic test for FLM that does not require
performance of thin-layer chromatography is:
A. AFP levels
B. Amniotic acetylcholinesterase
C. Amniostat-FLM
D. Bilirubin scan

Answer 20

C. Amniostat-FLM

Question 21

Does the failure to produce bubbles in the Foam Stability Index indicate increased or decreased lecithin?
A. Increased
B. Decreased

Answer 21

B. Decreased

Question 22

The presence of phosphatidyl glycerol in amniotic fluid fetal lung maturity tests must be confirmed when:
A. Hemolytic disease of the fetus and newborn is present
B. The mother has maternal diabetes
C. Amniotic fluid is contaminated by hemoglobin
D. A neural tube disorder is suspected

Answer 22

B. The mother has maternal diabetes

Question 23

A lamellar body count of 50,000 correlates with:
A. Absent phosphatidyl glycerol and L/S ratio of 1.0
B. L/S ratio of 1.5 and absent phosphatidyl glycerol
C. OD at 650 nm of 1.010 and an L/S ratio of 1.1
D. OD at 650 nm of 0.150 and an L/S ratio of 2.0

Answer 23

D. OD at 650 nm of 0.150 and an L/S ratio of 2.0