Amniotic Fluid

Question 1

Amniotic Fluid is present in the?

Answer 1

Amnion

Question 2

How is Amniotic fluid volume regulated?

Answer 2

production of fetal urine and lung fluid and absorption from fetal swallowing.

Question 3

What is intramembranous flow?

Answer 3

Absorption of amniotic fluid water and solutes into the fetal vascular system.

Question 4

Amniotic fluid increases throughout pregnancy, when does it reach its peak and how much?

Answer 4

1L in third trimester

Question 5

What is the major contributor to amniotic fluid volume?

Answer 5

fetal urine

Question 6

What regulates the increase in fluid volume from fetal urine?

Answer 6

fetal swallowing

Question 7

Failure of fetus to swallow resulting in excessive accumulation of amniotic fluid is called?

What does this indicate?

Answer 7

• Polyhydraminos
• fetal distress

Question 8

What is the ultimate source of amniotic fluid water and solutes?

Answer 8

Placenta

Question 9

How does the composition of amniotic fluid change with fetal production of urine?

Answer 9

• Increase - creatinine, urea and uric acid
• Decrease - glucose and protein

Question 10

Prior to 36 weeks gestation, what is the amniotic fluid cratinine range?

What happens when it rises above?

Answer 10

• 1.5 - 2.0 mg/dL
• >2.0 a means of determining fetal age

Question 11

In amniotic fluid:

Creatinine and urea does not exceed?

How much creatining and urea is found in urine?

Answer 11

• Creatinine 3.5 mg/dL
• Urea 30 mg/dL
• Creatinine 10 mg/dL
• Urea 300 mg/dL

Question 12

What test can differetiate amniotic fluid from urine?

What is a positive result?

Answer 12

• Fern test
• Fern-like crystals present in vaginal smear

Question 13

How is Amniotic fluid collected?

Answer 13

Aminocentesis

Question 14

How much amniotic fluid is drawn?

What is done with the first 2 - 3 mL?

Answer 14

• 30mL
• disgarded as may be contaminated with maternal blood

Question 15

Aminiotic fluid specimens for cytogenetic tests should be kept at?

Answer 15

room temp

Question 16

What test differentiates wource of blood (maternal or fetal) in amniotic fluid?

Answer 16

Kleihauer-Betke test for fetal hemoglobin

Question 17

What produces a green color in amniotic fluid?

Answer 17

Merconium (newborns first poop)

Question 18

A very dark brown color is associated with?

Answer 18

fetal death

Question 19

Hemolytic Diseases of the Newborn (HDN) The destruction of fetal red blood cells and appearance of What RBC degration product?

What is measure to determin the extent of hemolysis?

Answer 19

• unconjugated bilirubin
• Bilirubin

Question 20

Measurement of amniotic fluid bilirubin done byspectrophotometric analysis.

Optical Density (OD) of fluid is measured in intervals between?

What is th OD in normal fluid?

What is the OD when bilirubin is present?

Answer 20

• 365 nm - 550nm
• 365 nm and decreases to 550nm
• rise seen at 450nm

**** Absorbace difference is plotted on a Liley graph

Question 21

The lily graph plot the difference in absorbance against?

How many zones afre there and what is each ones significance?

Answer 21

• Gestational age
• three zones
  • Zone 1 mildy affected
  • Zone 2 careful monitoring required
  • Zone 3 severly affected, intervention throu induction of labor or intrauterine transfer

Question 22

Increased levels of alpha-fetoportein (AFP) are indicative of?

Increased levels are found where and why?

Answer 22

• Neural tube defects
  
  • anacephaly
  • spina bifida
• maternal serum and amniotic fluid when skin fails to close over neural tissue

Question 23

AFP levels are reported as?

What value is considered abnormal?

Answer 23

• MoM (multiples of the median)
• A value 2x the median value (>2 MoM)

Question 24

Elevated AFP levels are follwed by measurement of what test?

What is it more specific for?

Answer 24

Amniotic acetylecholinesterase (AChE)

Neural tube disorders, not done on a bloody specimen