AMNIOTIC FLUID

Question 1

colorless to pale yellow color found in the membranous sac that surrounds the fetus known as Amnion

Answer 1

AMNIOTIC FLUID

Question 2

AMNIOTIC FLUID Functions:

Answer 2

• cushion for fetus
• allows fetal movement
• stabilizes temperature
• proper lung development

Question 3

Normal volume:
* the volume of the amniotic fluid ______throughout the pregnancy
* the volume of the amniotic fluid gradually ______ before delivery

Answer 3

Normal volume: 800-1200mL during the 3rd trimester
* the volume of the amniotic fluid increases throughout the pregnancy
* the volume of the amniotic fluid gradually decreases before delivery

Question 4

ultimate source of amniotic fluid water and solutes

Answer 4

placenta

Question 5

during the 1st trimester, ____ of amniotic fluid is derived from the circulation coming from the mother

Answer 5

35mL

Question 6

the major constituent of amniotic fluid is fetal urine

Answer 6

After the 1st trimester

Question 7

the fetus can already release lung fluid, which then contributes to the volume of the amniotic fluid

Answer 7

During the 3rd trimester

Question 8

The normal volume of the amniotic fluid is regulated by the balance between the production of the fetal urine and lung fluid and absorption by:

Answer 8

1. fetal swallowing of amniotic fluid and
2. intramembranous flow

Question 9

Increase in the normal volume of the amniotic fluid (more than 1200mL)

Answer 9

Polyhydramnios

Question 10

Decrease in the normal volume of the amniotic fluid (less than 800mL)

Answer 10

Oligohydramnios

Question 11

Happens when there is decrease in the fetal swallowing of the urine and neural tube defects

Answer 11

Polyhydramnios

Question 12

• Happens when there is an increase fetal swallowing of urine
• Membrane leakage
• Urinary tract deformities (impaired
  urination → decreased fetal urine production)

Answer 12

Oligohydramnios

Question 13

Amniotic fluid Collection Method:

Answer 13

Amniocentesis

Question 14

Maximum volume we collect:

Answer 14

30 mL

Question 15

is discarded because it may be contaminated with maternal blood, tissue fluid, or cell

Answer 15

first 2-3mL

Question 16

the amniotic fluid we collect can be subjected for chromosomal studies (e.g., to detect trisomy21/down syndrome)

Answer 16

2nd trimester (approx. 16th week of pregnancy)

Question 17

can be used for assessment of fetal lung maturity and fetal hemolytic disease

Answer 17

3rd trimester

Question 18

• The amniotic fluid should be placed on ice during delivery
• Must be kept refrigerated if you will not perform the test immediately

Answer 18

Test for fetal Lung maturity

Question 19

Sample must be kept at room temperature or body temperature (37degC)

Answer 19

Test for Cytogenetic studies/Microbial studies

Question 20

To assess HDN is to detect bilirubin in amniotic fluid

Answer 20

Test for HDN (Hemolytic Disease of the Newborn)

Question 21

a photosensitive analyte and must be protected from light

Answer 21

Bilirubin

Question 22

Use ________bottle as a specimen container
▪ Alternatives:

Answer 22

amber-colored; foil and black plastic cover

Question 23

less reliable compared to urea and creatinine

Answer 23

Protein and glucose

Question 24

cases that when a mother has proteinuria or glucosuria

Answer 24

false positive maternal urine

Question 25

major metabolic products → high concentration in maternal urine

Answer 25

urea and creatinine

Question 26

Urea Value in: Amniotic Fluid Maternal Urine

Answer 26

Urea Value in: Amniotic Fluid <30mg.dL Maternal Urine >30mg/dL

Question 27

Creatinine Value in: Amniotic Fluid Maternal Urine

Answer 27

Creatinine Value in: Amniotic Fluid <3.5mg/dL Maternal Urine >10mg/dL

Question 28

detects ruptured amniotic membranes, aside from the 4 analytes

Answer 28

Fern Test

Question 29

Fern Test Specimen:

Answer 29

Vaginal fluid

Question 30

presence of fern-like crystals due to protein and sodium chloride

Answer 30

Amniotic fluid

Question 31

Amniotic fluid Appearance Colorless to pale yellow

Answer 31

Normal

Question 32

Traumatic tap, abdominal trauma, intraamniotic hemorrhage

Answer 32

Blood-streaked

Question 33

Increased bilirubin (seen on HDN)

Answer 33

Yellow

Question 34

Meconium (1st fetal bowel movement or newborn 1st poop)

Answer 34

Dark Green

Question 35

Fetal death/Fetal demise

Answer 35

Dark red brown

Question 36

Happens if there’s a presence of anti-D antibodies that can cross the placenta and destroys large number of fetal RBC → degradation of products (ie. Bilirubin)

Answer 36

HDN/ Erythroblastosis fetalis

Question 37

test for HDN

Answer 37

Optical density 450 (OD450)

Question 38

Absorbance of Amniotic fluid: Increased at 365nm and decreased at 550nm

Answer 38

Normal

Question 39

Absorbance of Amniotic fluid: Increased at 450nm (wavelength of maximum bilirubin absorbance)

Answer 39

HDN

Question 39

Results are plotted on a

Answer 39

Liley Graph

Question 40

nonaffected/mildly affected fetus (normal fetus)

Answer 40

Zone I

Question 41

moderately affected fetus and close monitoring is required to prevent severe effect of HDN

Answer 41

Zone II

Question 42

severely affected fetus and requires interventions

Answer 42

Zone III

Question 43

Interferences that may occur when performing this test:

Answer 43

o Presence of cells o Presence of meconium o Presence of debris o Presence of Hgb – peak absorbance of Hgb is 410nm → high absorbance of amniotic fluid