amniotic fluid Flashcards
frequently associated w/ cytogenetic analysis.
Amniotic fluid exam
it is a product of fetal metabolism
amniotic fluid
amniotic fluid is present in a membranous sac that surrounds the fetus called ____
amnion
FUNCTIONS OF AMNIOTIC FLUID
1) To provide a protective cushion for the fetus
2) Allow fetal movement
3) Stabilize temperature to protect the fetus from extreme temperature changes
4) To permit proper lung development.
Amniotic fluid volume is regulated by a balance between the production of ________ & the absorption from _________-.
fetal urine & lung fluid ; fetal swallowing & intramembranous flow
absorption of amniotic fluid water and solutes into the fetal vascular system.
Intramembranous flow
The amount of amniotic fluid increases throughout ________, reaching a peak approximately ______ during the 3rd trimester, & then gradually decreases prior to ______.
pregnancy ; 1 liter ; delivery
During the 1st trimester, the approximately _____ of A.F derived primarily from the _______.
35ml/g ; maternal circulation
After the 1st trimester, _______ is the major contributor to the A.F. volume.
Fetal urine
When fetal urine production occurs, fetal swallowing of A.F. ______ & _____ the increase in fluid from the fetal urine.
begins ; regulates
excessive accumulation of A.F. resulting from the failure of the fetus to begin swallowing.
Polyhydramnios
Polyhydramnios indicates ________, often associated w/ _________.
fetal distress ; neural tube disorders
decreased A.F. due to increase fetal swallowing, urinary tract deformities, & membrane leakage.
Oligohydramnios
Oligohydramnios is associated with ______, resulting in __________-.
umbilical cord compression ; decelerated heart rate & fetal death.
Ultimate Source of AF & solutes.
PLACENTA
Amniotic fluid has a composition similar to that of the maternal plasma and contains a small amount of sloughed fetal cells from the ____
DUS (Digestive system, Urinary tract, Skin)
Amniotic fluid also contains Biochemical substances produced by the fetus, such as _____
BELPEN (Bilirubin, Enzymes, Lipids, Proteins, Electrolytes, Nitrogenous compounds)
BELPEN can be tested to ______
determine the health or maturity of the fetus.
used to determine fetal age.
creatinine measurement
Prior to 36 weeks gestation , the amniotic fluid creatinine level ranges bet _______
1.5 and 2.0 mg/dl.
the amniotic fluid creatinine level rises above _____ providing a means of determining fetal age as greater than _____.
2.0 mg/dl ; 36 weeks
Levels of creatinine and urea are much lower in _____ than in _____.
amniotic fluid ; urine
AMNIOTIC FLUID: creatinine does not exceed _____; urea does not exceed _____.
3.5 mg/dl ; 30 mg/dl
URINE: as high as ______ for creatinine; and ______ for urea.
10 mg/dl ; 300 mg/dl
differentiate amniotic fluid from urine
Fern test
in Fern test, _____ specimen or smear is examined microscopically
Vaginal fluid
Fetal epithelial cells in AF can be examined for chromosome abnormalities by:
1) Karyotyping
2) Fluorescence in situ hybridization (FISH)
3) Fluorescent mapping spectral karyotyping (SKY)
4) DNA testing
Biochemical substances produced by the fetus can be analysed by ________ and _________ to evaluate the health of the fetus.
Fluorescence polarization ; Thin-layer chromatography
Amniocentesis may be indicated at 15-18 weeks of gestation to determine early treatment or intervention:
1) Mother’s age of 35 or more at delivery
2) Family history of chromosome abnormalities such as down
syndrome (trisomy 21)
3) Parents carry an abnormal chromosome rearrangement
4) Earlier pregnancy or child w/ birth defect
5) Parent is a carrier of metabolic disorder
6) History of genetic diseases such as:
- sickle cell disease
- sickle cell anemia
- tay sach disease
- hemophilia
- muscular dystrophy
- huntington chorea
- cystic fibrosis
7) Elevated maternal serum alpha fetoprotein
8) Abnormal triple marker screening test
9) Previous child w/ neural tube disorder such as spina bifida
or ventral wall defects
10) 3 or more miscarriages