AMNIOTIC FLUID Flashcards
purpose of amniotic fluid examination: (2)
- extent of fetal distress and maturity
- ability of the fetus to survive and early delivery
membranous sac
that surrounds the fetus
amnion
functions of amniotic fluid (5)
- cushion
- fetal movement
- heat absorber
- lung development
- exchange of nutrient
amniotic fluid volume
1st trimester:
3rd trimester:
- 35mL
- 1L
absorption of amniotic fluid water
and solutes into the fetal vascular system
intramembranous flow
Excessive accumulation of amniotic fluid
from failure of fetus to swallow
polyhydramnios
Decreased amniotic fluid from increased
fetal swallowing
oligohydramnios
fetal age can be estimated by measuring _____
give also the values
creatinine
<36 weeks 1.5-2.0 mg/dL
>36 weeks >2.0 mg/dL
how to differentiate maternal urine vs amniotic fluid
creatinine, urea, glucose, and protein
amniotic fluid:
<3.5 mg/dL
<30 mg/dL
rgt strip + for protein and glucose
specimen collection volume and special consideration
a. 30
b. 40
c. 50
d. 60
- volume: 30 mL
- discard first 2-3mL because of maternal blood
- protect the spx from light
this test requires ice and cooled/frozen for up to 72 hrs if needed
fetal lung maturity test
these tests require aseptic collection and 37C temp
cytogenetic
microbiology
these tests needs centrifuge or filter fluid to remove debris
chemical tests
normal color of amniotic fluid
colorless with slight to moderate turbidity from cells
blood-streaked amniotic fluid
traumatic tap
intra-amniotic hemorrhage
test to differentiate maternal vs fetal blood
Kleihauer-Betke test
bright yellow amniotic fluid
increased bilirubin
dark green amniotic fluid
meconium
dark red brown amniotic fluid
fetal death
this fetal disease is commonly found on Rh (-) pregnant mothers
hemolytic disease of the newborn
when can HDN happen?
second pregnancy
which analyte is measured in case of HDN
bilirubin
liley graph zone I
mildly affected fetus
liley graph zone II
requires careful monitoring
liley graph zone III
severely affected fetus, may require induction of labor
marker for neural tube defects
alpha fetoprotein
increased levels of AFP may indicate:
anencephaly or spina bifida
more specific marker for neural tube defects
acetylcholinesterase
common complication of early delivery
respiratory distress syndrome
reference method for FLM
lecithin/sphingomyelin ratio
primary component of the lung surfactant; increased production after 35th week
lecithin
produced at a constant rate after the 26th week to control its counterpart
sphingomyelin
L/S ratio required to consider a safe preterm delivery
a. 1
b. 2
c. 3
d. 4
> 2.0
how is L/S ratio performed?
thin-layer chromatography
is an agglutination test using
antibody specific for phosphatidyl glycerol that can
replace the L/S ratio
amniostat-FLM
advantage of amniostat-FLM (2)
- no special equipment needed
- blood and meconium do not interfere with the test
this test can be performed at the bedside, amniotic fluid is mixed with 95% ethanol
foam stability
a value of >___ indicates FLM
a. 45
b. 46
c. 47
d. 48
47
Measures the polarization of a fluorescent dye that
binds to surfactant and albumin
microviscosity: fluorescence polarization
storage form of lung
surfactants
lamellar bodies
which cells secrete lamellar bodies?
type II pneumocytes
T or F. lamellar bodies resemble small platelets thus can be counted using platelet analyzers
true
T or F. presence of lamellar bodies decreases the OD of the fluid
false
lamellar body count that indicates FLM
a. >30, 400
b. >25, 400
c. >40, 400
d. >35, 400
> 35, 400
mg of surfactant required per g of albumin in microviscosity for FLM
a. 50
b. 55
c. 60
d. 65
55
