Chapter 6 - Antepartal Tests Flashcards
Screening
not definite
-designed to ID those who are NOT affected by a diasease or abnormality
Diagnostic Tests
give a definite yes or no re if fetus is normal or abnormal
Types of Screening Tests
- AFI
- BPP
- CST
- daily FKC
- multimarker screening [AFP, triple/quad marker)
- NST
- ultrasonography
- nuchal translucency
- umbillical artery doppler flow
- VAS
Types of Diagnostic Tests
- amniocentesis
- CVS
- MRI
- PUBS
- ultrasonography
types of biophysical assessments
- ultrasonography
- umbilical artery doppler flow
- MRI
- *alll screen, not diagnstc
Amniocentesis
needle is inserted thru abdominal wall to get amniotic fluid
- 15 20 wk
- diagnostic for cell growth + chromosomal
Amniocentesis
results
- high bilirubin= hemolytic disease
- pos culture= infectn
- L/S > 2:1 is mature lungs
- L/S < 2:1 immature, risk for RDS
- pos PG= mature lungs
- neg PG = immature
- LBC>50K= mature lungs
- LBC<50K= immature
Amniocentesis risks
- loss
- trauma to fetus/placenta
- bleed/leak of amnio fluid
- preterm labor
- mom infectn
- Rh sensitization bc risk for blood mixing
PUBS percutaneous umbilical blood sampling
- removal of fetal blood fr umbilical cord
- diagnostic test for metab, hematologic, disorders, fetal infectn, fetal karyotyping
- 18 wks
PUBS risks
- loss
- trauma to fetus/placenta
- bleed/leak of amnio fluid
- preterm labor
- mom infectn
- Rh sensitization bc risk for blood mixing
Types of maternal assays
- AFP/MSAFP
- Triple Marker Screen
- Quad Marker Screen
Alpha-FetoProtein [AFP]
aka
Maternal Serum AFP [MSAFP]
AFP is a glycoprotein produced by the fetal liver, GI tract + yolk sac in early gestation
- screening tool for NTD + ventral wall defects
- 15-20 wks
high levels of AFP
- NTD
- anencephaly
- omphalocele
- gastroschisis
low levels of AFP
-trisomy 21 aka down syndrome
abnormal AFP findings will require additional testing such as…
- amniocentesis
- CVS
- ultrasonography
AFP has a high risk for…
false positives
Triple Marker Screen/Quad Marker Screen
- triple: AFP, hCG, + estriol
- quad: +inhibin A
- tests for trisomy (down syndr) + NTD
- 15-16 wks
high levels of hCG + inhibin A
trisomy 21 (down syndrome)
low levels of estriol
Down syndr
Fetal Kick Count FKC
- kicking starts at 16-20wk
- utilized after 28 wks
- palpate ab + track mvmt for 1-2 hrs
FKC norm + abnorm
norm: 10+ w/in 2 hrs; 4+ in 1 hr
abnorm: less than 4 in 4 hrs, contact HCP
Non Stress Test
monitors FHR pattern + acceleration to assess oxygenation
-monitor for 20-40 min
norm/reactive NST
2 or more accells in 20 min
<32wk, 2 accells (10 bpm + 10 secs) in 20 min period
nonreactive NST
no sufficient FHR in 40 min
nonreactive NST should be followed up w…
ultrasound or BPP
-give juice, reposition, VAS
presence of repetitive variable decel that last ____ requires further assessment of ____
> longer than 30 sec
amniotic fluid or prolonged monitoring
vibroacoustic stim VAS
used when NST is nonreactive
-repeated in 1 min intervals for 3 times
VAS is CI in…
deceleration or bradycardia
reactive VAS
2 or more accells in 20 min
<32wk, 2 accells (10 bpm + 10 secs) in 20 min period
contraction stress test CST
fka oxytocin challenge test
- assess ability to maintain FHR in response to UC in women w nonreactive NST at term
- screens risk during delivery
CST procedure
- monitor FHR for 20 min
- if no spontaneous UC, then stim nipples for 10 mins (to produce oxytocin) or admin IV oxytocin
normal/negative result in CST
no significant var.decel or no late.decel in 10 min strip w 3 UC
positive results in CST
late decel w half of UC
pos result in CST is linked w…
- incr fetal death
- fetal growth restriction
- lower 5 min apgar score
- c section
- need for neonatal resuscitation
admin of oxytocin during CST places mom at risk for..
tachysystole
-more than 5 UC in 10 min
AFI
screening to measure volume of amniotic fluid
-based on fetal urine production
in prolonges fetal hypoxemia…
blood is shunted away fr kidneys to other vital organs
|»_space;decr in amniotic fluid production
norm/avg AFI
8 - 24 cm
low AFI
less than 5 cm
- oligohydramnios
- incr prenatal mortality
high AFI
more than 24 cm
- polyhydramnios
- NTD, GI obstruction, or hydrops
BPP
30 min ultrasound screening for fetal status w NST
BPP asses 5 variables
1 FHR reactivity 2 fetal mvmt 3 tone 4 breathing 5 amniotic fluid vol
BPP mvmt score
2: 3+ trunk/limb mvmt
0: less than 3
BPP tone score
2: 1+ active extension + return to flexion
0: absent mvmt
BPP breathing score
2: 1+ breathing lasting 30 sec
0: absent breathing or less than 30s of sustained breathing
BPP amniotic fluid
2: at least one pocket measures 2cm
0: absent pocket
NST in BPP score
2: reactive
0: nonreactive
BPP scoring results
8/10: reassuring
6/10: equivocal, may need more testing
4/10: non-reassuring, needs more eval or delivery
2/10: immediate delivery
nuchal translucency
checks fluid on neck
- 18 wks
- incr risk for chromosomal disorders
abdominal ultrasound requires….
full bladder
fetal ultrasound
to obtain info on:
- gestatl age
- growth/anatomy
- amt amniotc fluid
- placentl sytat
- nuchal transluscency
is fetal ultrasound invasive?
no,
noninvasive, no risks, + accurate
MRI purpose
to check tissue, organ, vasc structure
MRI requires…
iodine contrast. drink lots of fluid
-supine w left lateral tilt to prevent hypotension
Doppler flow studies
noninvasive screening to assess BF to placenta
-calculated by using difference bw sys vs diastole flow
umbilical artery doppler results is considered abnormal if..
sys/dias ratio is above 95th percentile for age or above 3.9 or en-diastole flow is absent or reversed
