DIAGNOSTICS (3) Flashcards
chorionic villi sampling - CST
transcervical or transabdominal insertion of a needle into the fetal portion of the placenta.
chorionic villi sampling
cvs is performed at what weeks gestation?
8-12wks
what are examined to detect chromosome abnormalities and genetic disorders such as?
- chorionic villi cells
- down syndrome
- cystic fibrosis
this is done at 8-10 wks of pregnancy wherein chorionic cells are located by ultrasound
biopsy & analysis of chorionic villi for chromosomal analysis
what is the other term for chorionic villi sampling?
biopsy of placenta
as a nurse on duty, what should you instruct your client after the chorionic villi sampling procedure?
to report bleeding, infection, or leakage of fluid after procedure
(CVS)
as a nurse on duty, you should be aware of the reportable s/sx the patient should look out for. what are these?
- chills or fever (infection)
- uterine contraction / vaginal bleeding (threatened miscarriage)
what test involves measurement of AFP, estriol, and hCG in maternal serum?
AFP/Triple Screen
at what week of gestation is AFP/Triple Screen is being tested? and what is its purpose?
- 15-20wks
- screen for fetal structural & chromosomal abnormalities
what is alpha-feto protein?
substance produced by the liver that is present in the amniotic fluid and maternal serum
if this is detected as abnormal, the woman is next referred for ultrasound to confirm gestational age and to evaluate neural tube defects & other structural abnormalities.
estriol
what is often associated with Trisomy 21 (down syndrome) ?
low estriol, elevated hCG, low AFP
what is associated if the fetus has an open spinal or abdominal defect?
high in maternal serum (MSAFP)
this test assess fetal well-being that analyses the response of the fetal heart to fetal movement.
non-stress test (NST)
what does accelerations of FHR with fetal movement indicates?
the fetus has adequate oxygenation and intact CNS
how can you tell that the fetus has a reactive NST? is this a good sign?
baby’s heart rate should accelerate by 15 beats for at least 15 seconds, twice in a 20min period. this is a sign that the baby is healthy
what does reactive NST indicates?
intrauterine survival for one week.
as the nurse on duty, what preparation should you do for the mother before the NST?
feed with food or fluids before the test to stimulate fetal movements
this assesses the ability of the fetus to withstand the stress of uterine contraction done during labor
contraction stress test (CST)
CST is a means of evaluating the?
respiratory function of the placenta
induced or spontaneous contraction results in?
decrease transport of O2 to the fetus.
if placental reserve is insufficient, what can occur?
fetal hypoxia and decrease in FHR
when is contraction stress test initiated?
3 contractions in every 10 minutes.
what is accelerations?
temporary normal increases in FHR caused by fetal movement / compression of umbilical vein during contraction
this is the periodic decreases in FHR resulting from pressure of the fetal head during contractions.
- begins when contraction starts, ends when contraction ends
Early Decelerations
what are late decelerations?
delayed decelerations until 30-40 seconds after onset of a contraction and continue beyond the end of contraction.
what do you call the lowest point of deceleration that occurs near the end of the contraction instead of at its peak?
Nadir
what sign shows uteroplacental insufficiency ?
ominous pattern in labor
what is uteroplacental insufficiency?
decreased blood flow through the intervillous spaces of the uterus during contractions.
late decelerations occur with what? or with abnormal uterine tone caused by administration of what?
- hypertonia
- oxytocin
as the nurse on duty, you saw that your patient is having late decelerations. what nursing intervention would you do?
- stop or slow administration of oxcytocin
- change position to lateral (left) to relieve pressure from vena cava
- administer IVF or O2 as prescribed.
if late decelerations persist, what should you prepare for? why do you need to do it?
- deliver the infant
- may lead to fetal death
what are variable decelerations?
decelerations that occur at unpredictable times in relations to contractions
what may cause variable decelerations?
- compression of cord ( cord prolapse )
- fetus is lying on the cord
- oligohydramnios
as the nurse on duty, you saw that your patient is having variable decelerations. what nursing intervention should you do ?
- change into T-position
- administer fluids and O2 as prescribed
- if not relieved, amnioinfusion may be prescribed
if the interpretation result of CST shows that there is persistent late decelerations with more than half the contractions, what does this indicate?
a positive result. fetus is no longer receiving adequate oxygen. needs to be delivered
how can you say that the interpretation result of CST is negative?
- no late decelerations in 10 min period
- it is safe for the fetus to remain in utero for the next 7 days