FINALS - AMNIOTIC FLUID Flashcards
Amniotic Fluid is found in the ___ providing a cushion for protection (amnion)
membranous sac that surrounds the fetus called AMNION
how do amniotic fluid are formed?
Formed from the metabolism of fetal cells, transfer of water across
the placental membrane and in the 3rd trimester by fetal urine.
The ____ is metabolically active and is involved in the exchanges of water and
chemicals between the fluid, the fetus, and the maternal circulation; and produces peptides, growth factors, and cytokines.
amnion
what are the functions of amniotic fluid
➔ Provides a protective cushion for the fetus
➔ Allows fetal movement
➔ Stabilize the temperature to protect the fetus from extreme temperature changes
➔ Permits proper lung development
amniotic fluid balance is regulated by the balance between what production and processes?
Regulated by the balance between the production of fetal urine and
lung fluid, and absorption from fetal swallowing and
intramembranous flow
do amniotic fluid increases or decreases during the course of pregnancy
Volume INCREASES on the course of pregnancy reaching a
peak of approximately 800 to 1200 mL during the third trimester, and then gradually DECREASES prior to delivery
what is the volume of the amniotic fluid During the first trimester
Amniotic fluid is derived from the MATERNAL CIRCULATION
(35mL)
what is the major contributor of amniotic fluid after the first trimester
Urine is the major contributor of amniotic fluid
after the first trimester, ____ starts to regulates the increase in fluid from the fetal urine
Fetal swallowing
the lung fluid secreted will help the fetus lungs to develop, every respiratory movement of the fetus, the lung fluid will enter the amniotic fluid, bathing the lungs and washing the pumonary and alveolar contents such as the ______
these are the lung surfactant that serve as an index of fetal lung maturity. What are those?
lecithin, sphingomyelin, and phosphatidylglycerol
what is happening in the latter third to half of the pregnancy in terms of the amniotic fluid’s volume?
Fetus secretes a volume of lung liquid which will enter the amniotic fluid
An amniotic fluid volume greater than ___ is called polyhydramnios,
1200 ml
amniotic fluid volume less than___ is
termed oligohydramnios
800 mL
Abnormal increase of the fluid volume
Polyhydramnios
polyhydramnios is caused by the ___
Accumulation of amniotic fluid due to fetus’
failure to swallow the urine
the failure to swallow amniotic fluid of the fetus is mainly caused by the
a. Fetal distress
b. Neural tube defects
c. Secondary effects like congenital infection, urinary tract deformities
in the book, secondarily associated to fetal
structural anomalies, cardiac arrhythmias, congenital infections or chromosomal abnormalities.
Abnormal decrease amniotic fluid
Oligohydramnios
Oligohydramnios is associated with what conditions
a. Umbilical cord compression
b. Decelerated heart rate
c. Fetal Death
The ___ is the ultimate source of amniotic fluid water and solutes
placenta
the sloughed fetal cells will provide the basis for the
cytogenetic analysis.
the chemical composition of the amniotic fluid is similar to the composition of the ___
maternal plasma
the chemical composition of the amniotic fluid contains the sloughed fetal cells such as from the ___
o From the Skin
o From the digestive system
o From the urinary tract
Biochemical substances found in the amniotic fluid that are produced by the fetus
o Bilirubin
o Lipid
o Enzymes
o Nitrogen compound protein
in the book;
electrolytes, urea, creatinine, uric acid, proteins, and hormones
it is Used to determine fetal age
Amniotic Fluid Creatinine
Prior to 36 weeks of gestation, the creatine level is
1.5-2.0 mg/Dl
> 2,0 mg/dL creatinine will indicate the age of the fetus which is
this indicates >36 weeks gestation
the testing of amniotic fluid is frequently associated with ___
cytogenetic analysis
cytogenetic analysis When conditions that adversely
affect the fetus arise, the danger to the fetus must be measured
against the ability of the fetus to survive an early delivery.
true or faLse
TRUE- cytogenetic analysis will measure kung kaya ba ni baby masurvive the premature delivery once there’s a danger
which condition or defect allows the fetal cerebrospinal fluid to enter the amniotic
fluid directly.
Neural tube defects
___ and ___ are two biochemical markers tested for neural tube defect
Alpha-fetoprotein and acetylcholinesterase
when the fetal urine production begins, what are the biochemical components of the amniotic fluid that will increase and will decrease?
since urine is involve, the nitrogen compound proptein will increase
creatinine, urea, and uric acid increase,
and glucose and protein will decrease
to distinguished amniotic fluid and maternal fluid, the level of creatinine and urea are much lower in amniotic fluid than in the normal urine
true or false
true
Creatinine does not exceed ___ and urea does not exceed ___ in amniotic fluid
3.5 mg/dL; 30 mg/dL
is glucose and protein a reliable indicator or marker for differentiating amniotic fluid and urine
nope as it is an uncommon urine constituent
what test also can differentiate amniotic fluid from urine and other body fluids.
The fern test
It is a test used to evaluate premature rupture of the membranes
fern test
how do fern test is conducted?
a vaginal fluid specimen is spread on a glass slide and allowed to completely air dry at room temperature; then it is observed microscopically. The presence of “fern-like” crystals due to the protein and sodium chloride content is a positive screen for amniotic fluid.
The presence of “______” crystals due to the
protein and sodium chloride content is a positive screen for amniotic fluid in the fern test
fern-like
is recommended for neural tube defects when screening blood tests such as when the maternal serum alphafetoprotein test are abnormal or to detect genetic disorders or to evaluate the health of the fetus
amniocentesis
used to estimate gestattional age of the fetus aside from the creatinine and provide assessment to the size and growth of the fetus
it can take the fetal body measurement as well
fetal ultrasonography
___ in amniotic fluid indicate the genetic material of the fetus and the biochemical substances that the fetus has produced.
Fetal epithelial cells
Biochemical substances produced by the fetus can be analyzed by ___to evaluate the health of the fetus
thin-layer chromatography
Amniocentesis may be indicated at ___ gestations to determine the early treatment or intervention
15 to 18 weeks
can we conduct amniocentesis in a mother aging 34 younger?
No, the mother’s age should be 35 or older at delivery
can we conduct amniocentesis if the patient’s family history has chromosome abnormalities such as trisomy 21 or down syndrome
yes,
can we conduct amniocentesis in if the parents carry an abnormal chromosome arrangement?
yes
can we conduct amniocentesis if the earlier pregancy has a birth defect?
yes
can we conduct amniocentesis if there’es an elevated maternal serum alpha-fetoprotein?
yes
can we conduct amniocentesis the patient has been in 3 or more miscarriage?
yes
Amniocentesis is indicated later in the pregnancy (20 to 42 weeks) to evaluate ___
- Fetal lung maturity
- Fetal distress
- HDN caused by Rh blood type incompatibility
- Infection
what can we perform in the Early (14-16 weeks) of pregnancy
Diagnosis of Genetic Diseases
what can we perform in the mid trimester of pregnancy
Bile Pigments level for HDN
what can we perform in the 3rd trimester of pregnancy
Renal maturity
Bile pigments level for HDN
Amniotic fluid is obtained by needle aspiration into the amniotic sac, a procedure called ___
amniocentesis
In amniocentesis, The procedure
most frequently performed is a ___
transabdominal amniocentesis.
Using continuous __ for guidance, the physician locates the fetus and placenta to safely perform the procedure
ultrasound
a type of amniocentesis may also
be performed; however, this method carries a greater risk of
infection.
Vaginal amniocentesis
A maximum of ____ of amniotic fluid is collected in sterile syringes
30 mL
The first ____mL collected can be contaminated
by maternal blood, tissue fluid, and cells and are DISCARDED.
2 or 3 ml
Fluid for bilirubin
analysis in cases of ____ must be protected from light at all times.
hemolytic disease of the newborn (HDN)
Fluid for fetal lung maturity (FLM) tests should be placed in____
ice for delivery to the laboratory and kept refrigerated
Can be kept for 72 hrs in refrigerator
Repeat freeze-thawing is not recommended
Filtration is recommended for this method to
prevent phospholipid loss
Transport with ice if for phospholipid
determination
is Repeat freeze-thawing recommended for the specimen used for fetal lung maturity test
No
In fetal lung maturity test, what is recommended for this method to
prevent phospholipid loss
filtration
in fetal lung maturity test, the sample should be transported with ____ if for phospholipid determination
ice
in cytogenetic studies, the sample must be maintained at ____ or at ____
room temperature or at body
temperature (25 or 37˚C)
All fluid for chemical testing should be separated from cellular elements and debris as soon as possible to prevent distortion of chemical constituents by cellular metabolism or disintegration. This can be performed using ___ or __
centrifugation or filtration.
NORMAL color of the amniotic fluid
colorless to pale yellow
normal volume of amniotic fluid
1000-1500 mL at term (36 weeks)
clinical correlation of the blood streak in amniotic fluid
traumatic tap
abdominal trauma
intra-amniotic hemorrhage
The source of the blood (maternal or fetal) can be determined using the _____test for fetal hemoglobin and is important for further case management
Kleihauer-Betke
clinical correlation of colored yellow amniotic fluid
hemolytic disease of the newborn (bilirubin)
clinical correlation of the dark green colored amniotic fluid
meconium
clinical correlation of the dark red-brown colored amniotic fluid
fetal death
what is the normal color of the maternal urine
yellow
creatinine value of amniotic fluid
3.5 mg/dl
creatinine level of maternal urine
10 mg/dl
urea level of amniotic fluid
30 mg/dl
urea level of maternal urine
300 mg/dl
is glucose and protein present in amniotic fluid?
yes
is glucose and protein present in maternal urine?
nope
surface fluids or surfactants of the fetal lung fluid
lecithin
sphingomyelin
phosphatidyl glycerol
Primary surface liquid
lecithin
a surfactants that is Produced at relatively low and constant rate
until 35th week of gestation
lecithin
a surfactant that is Produced at constant rate after about 26th week
of gestation
sphingomyelin
Essential fluid for adequate lung maturity
Phosphatidyl
glycerol
a normal Lecithin/sphingomyelin ratio
Mature = >2.0
normal Saturated phosphatidyl-choline value
> 500 ug/L
an abnormal Lecithin/sphingomyelin ratio
Immature = <1.5
Transitional = 1.5-1.9
how do hemolytic disease of the newborn starts?
when fetal red blood cells enter into the maternal circulation and stimulate the mother to produce antibodies to the antigen. When these antibodies present in the maternal circulation cross the placenta into the fetal circulation and bind to the antigen on the fetal cells, the cells are destroyed.
rbc ni fetal napunta sa circulation ni mother, mother creates antibodies for the fetal rbc. The antibody cross the placenta and attached to the rbc antigen of the fetal causing rbc degradation –> anemia
rbc ni fetal napunta sa circulation ni mother, mother creates antibodies for the fetal rbc. The antibody cross the placenta and attached to the rbc antigen of the fetal causing rbc degradation –> anemia
this degradation results to a product of
unconjugated bilirubin in the amniotic fluid
since there’s degradation of the fetal rbc happening in the HDN, the amount of ___ is can me measured and the extent of the hemolysis taking place can be determines as well as the danger of the anemia presents to the fetus may be assesed
unconjugated bilirubin
Amniotic fluid bilirubin is measured by ___
spectrophotometric analysis using serial dilutions
In amniotic bilirubin spectrophotometry for HDN,
When bilirubin is present, a rise in Optical Density is seen at ____nm because this is the wavelength of maximum bilirubin absorption.
450
the difference in Optical Density, referred to as the absorbance difference at 450 nm (D A450), is then plotted on a __ to determine the severity of the hemolytic disease
Liley graph
in HDN - bilirubin determination, Markedly decreased values will be obtained with as little as _____ minutes of exposure to light.
30 minutes
in HDN - bilirubin determination,
Specimens contaminated with meconium will cause falsely ___D A450 values and are not acceptable for spectrophotometric analysis
low
in HDN - bilirubin determination,
Specimens that are contaminated with blood are generally unacceptable because maximum absorbance of oxyhemoglobin occurs at ___nm and can interfere with the bilirubin absorption peak
410
the interference such as fluid by cells, hemoglobin, and meconium as well as blood for the bilirubin test for HDN can be removed by ____
extraction with chloroform if necessary
Measurement by spectrophotometric analysis and plotted in the lily curve
amniotic fluid bilirubin
Amniotic Fluid Bilirubin spectophotometry
Normal: Optical density will rise at ___and will decrease linearly at ____
365nm ; 550nm
in amniotic fluid bilirubin,
(+) Bilirubin: Optical density will be seen at ___ nm
450nm
Amniotic Fluid Bilirubin is Elevated in ___ and ___
hemolytic disease of the newborn HDN and Erythroblastosis fetalis
___ Plots A450 against gestational age
Liley Graph
liley graph’s 3 zones based on hemolytic severity
o Zone I: Mildly affected fetus
o Zone II: Requires careful monitoring
o Zone III: Severely affected fetus, may require induction of labor or intrauterine exchange transfusion
normal values of Bilirubin in 28 weeks
<0.075
normal values of Bilirubin in 40 weeks
<0.025
if the values of Bilirubin in 28 weeks is >0.075, it has a clinical correlation of
erythroblastosis hepatitis
if the values of Bilirubin in 40 weeks is >0.025, it has a clinical correlation of
maternal infection
sickle cells
Represent the measurement and reading of bilirubin from amniotic fluid plotted by spectrometer
liley’s curve
Most common in Rh-negative mothers
hemolytic disease of the newborn
Good indicator for the presence of infection in HDN in reagent strip
leukocyte esterase
Neural Tube Defects can be detected by
maternal serum alpha-fetoprotein (MSAFP) blood test,
high resolution ultrasound
and amniocentesis
wbc count if positive in HDN
> 50/ul
are one of the most common birth defects in the United States
neural tube defects
Increased levels of alpha-fetoprotein (AFP) in both the maternal circulation and the amniotic fluid can be indicative of fetal neural tube defects, such as ___ and ___
anencephaly and spina bifida.
Increased levels of alpha-fetoprotein (AFP) in both the maternal circulation and the amniotic fluid can be indicative of ____
fetal neural tube defects
___is the major protein produced by the fetal liver during early gestation (prior to 18 weeks).
Alpha feto-protein
Increased levels are found in the maternal
serum and amniotic fluid when the skin fails to close over the ____, as occurs in anencephaly and spina bifida.
neural tissue
The fetus produces maximal AFP between ___’ gestation, after which levels in amniotic fluid begin to decline.
12 and 15 weeks
The
____is the laboratory’s reference level for a given week of gestation.
median
Elevated amniotic fluid AFP levels are followed by measurement of ___.
amniotic acetylcholinesterase (AChE)
___
The test is more specific for neural tube disorders than AFP
provided it is not performed on a bloody specimen, because blood contains AChE.
amniotic acetylcholinesterase (AChE)
___, whether caused by HDN or other conditions, forces the obstetrician to consider a preterm delivery.
Fetal distress
____: Confirmatory test for neural tube disorders
Acetylcholinesterase Test
__is the most frequent complication of early delivery and is the seventh most common cause of morbidity and mortality in the premature infant
Respiratory distress syndrome (RDS)
purpose of surfactants
Surfactant keeps the alveoli from collapsing by decreasing surface tension and allows them to inflate with air more easily.
If the surfactant concentrations are too low, the alveoli will collapse, causing ___.
RDS - respiratory distress syndrome
The incidence of RDS ___with increasing gestational age and lung maturity
decreases
The amount of surfactant in fetal lungs can be estimated by measuring the ___
amount of surfactants in amniotic fluid
The reference method to which tests of fetal lung maturity are compared is ___
lecithin-sphingomyelin (L/S) ratio
___is the primary component of the surfactants (phospholipids, neutral lipids, and proteins) that make up the alveolar lining and account for alveolar stability
Lecithin
Lecithin is produced at a relatively low and constant rate until the ___week of gestation
35th
___is a lipid that is produced at a constant rate after about 26 weeks’ gestation
Sphingomyelin
it can serve as a control on which to base the rise in lecithin.
sphingomyelin
Prior to 35 weeks’ gestation, the L/S ratio is usually less than ___ because large amounts of lecithin are not being produced at this time
1.6
after 35 weeks of gestation, lecithin concentration ___while the sphingomyelin concentration remains constant
increases
from 1.6, the L/S ratio after 35 weeks of gestation will rise to
2.0 or higher as the lecithin production increases to prevent alveolar collapse.
Therefore, when the L/S ratio reaches 2.0, a preterm delivery is usually considered to be a relatively safe procedure
true or false
true
In L/S ratio test,
Falsely elevated results are encountered in fluid contaminated with __ or __ because both these substances contain lecithin and sphingomyelin
blood or meconium
Quantitative measurement of lecithin and sphingomyelin is performed using ___
thin-layer chromatography (TLC).
Because the procedure is labor intensive and subject to high coefficients of variation, many laboratories have replaced the L/S ratio with the quantitative ___ and ____ procedures.
phosphatidyl glycerol immunoassays
and
lamellar body density
Analytical Error for L/S ratio
o Over centrifugation
o Blood Contamination
o Imprecision of TLC
o Meconium
Essential for adequate fetal lung maturity
Phosphatidylglycerol and Phosphatidylinositol
Immunological agglutination test for phosphatidyl glycerol
Amniostat FLM
Provides rapid method for assessment of lung maturity
Amniostat FLM
Mechanical screening test to measure the individual lung surface lipid concentration
Foam Test
The production of ___normally parallels that of lecithin, but its production is delayed in cases of maternal diabetes
Phosphatidyl Glycerol
The __ uses antisera containing polyclonal anti-PG antibodies that are specific for PG-containing lamellar bodies in the amniotic fluid
Aminostat-FLM
test for fecal lung maturity that is not affected by specimen contamination with blood and meconium
Aminostat-FLM
Until the development of biochemical techniques to measure the individual lung-surface lipid concentrations, a mechanical screening test, called the “_____ “ or “____” test, was used to determine their presence
foam” or “shake
in foam shake test, what solution is used with a 95% concentration
ethanol
in foam or shake test using 95% ethanol mixed with amniotic fluid, how many seconds is the solution shaken and stand after?
15 secs and allowed to sit undisturbed for 15 minutes
an antifoaming agent used for shake or foam test
ethanol
a positive result of shake or foam test for FTM
continuous line of bubbles around the outside edge
sufficient amount of phospholipid is available to reduce the surface tension of the fluid
Surfactant is composed of approximately 90% phospholipid and 10% protein and is packaged into layered storage granules called ___
lamellar bodies
__ are densely packed layers of phospholipids that represent a storage form of pulmonary surfactant
Lamellar bodies
Lamellar bodies are secreted by the
type II pneumocytes of the fetal lung at about 24 weeks of gestation
are absorbed into the alveolar spaces to provide surfactant
lamellar bodies
