fetal surveillance Flashcards
testing should be as early as _ wks for women w/ worrisome conditions
26-28wks
maternal conditions indicated for antepartum surveillance
severe hypothyroidism symptomathic hgbpathy cyanotic heart ds chronic renal ds DM marked uterine anomalies
placental conditions indicated for antepartum surveillance
APAS SLE htn do thrombophilia marked placental anomalies
fetal conditions indicated for antepartum surveillance
dec fetal mvmt oligohydramnios polyhydramnios IUGR postterm pregnancy macrosomia fetal anomalies multiple gestations previous stillbirth
passive unstimulated activity commences as early as?
7 wks
fetal body mvmt are never absent for periods exceeding 13mins
8 wks
general body mvmt become organized
20-30 wks
clinical methods used to quantify fetal mvmt
tocodynamometer
utz
maternal subjective perception
2 types of respiratory mvmt
gasp/sighs (1-4/min)
irreg burst of breathing (240/min)
factors affecting fetal respiratory mvmt
hypoxia hypoglycemia sound stimuli cigarette amniocentesis impending preterm labor gestationla age FHR inc w/ maternal meals
respiratory motion in inspiration & expiration
I: chest collapse, abdomen expand
E: chest expand
NST is based on this hypothesis
FHR that is non-academic as a result of fetal hypoxia or neuro depression will temporarily accelerate in response to fetal mvmt
normal FHR acceleration per AOG
> 32 wks: >15bpm above baseline lasting >15 sec but <2min
<32 wks: >10bpm above baseline lasting >10 sec
procedure of NST
palpate for fetal back then secure doppler upon hearing fetal HR
palpate fundus then attach tocodynamometer
ask px to lie in LLD
start recording w/ minimum 25 mins monitoring
what is the normal NST?
reactive NST
- >2 accels peaking at >15bpm above baseline lasting >15sec all w/in 20min of test
NST can be extended unto >40mins to account for fetal sleep cycles? T or F?
true
what is the abnormal NST?
non-reactive NST
interval bet. testing for px w/ abnormal NST
7 days
ACOG: 2x a week for px with postterm gestation; pre-gestational DM; fetal growth restriction; htn
CST: late decelerations interpretation
utero-placental pathology
CST: variable deceleration interpretation
cord compression (oligohydramnios, placnetal insufficiency)
procedure of CST
FHR & uterine contractions are recorded simultaneously
>3 spontaneous uterine contractions of >40 sec in 10 mins are present, no uterine stimulation necessary
<3 spontaneous uterine contractions of >40 sec in 10 mins, induce contraction either w/ oxytocin or nipple stimulation
dose of oxytocin for inducing contraction
dilute IV infusion at rate of 0.5mU/min and doubled every 20 mins
what is the normal CST?
negative CST
no late or significant variable decels
what is the abnormal CST?
positive CST
uniform repetitive late FHR decels following >50% contractions
what is the equivocal or suspicious CST?
intermittent of significant variable decels but no late decels
what is the equivocal hyperstimulation?
FHR decels that occur in contractions more frequently than every 2 min or >90 sec
what is the unsatisfactory CST?
<3 contractions in 10 min or uninterpretable tracing
differentiate accels from decels
A: upward inc of baseline >15 beats for min lasting >15 sec
D: downward dec of baseline >15 beats for min lasting >15 sec
acoustic stimulation test mechanics
loud external sounds used to startle fetus provoking FHR accel
positive response is rapid accel
this is done when fetus is asleep
components of biophysical profile
HR accel breathing mvmt tone AFV
score of 2 for NST, breathing, mvmt, tone, & AFV
NST: reactive NST
breathing: >1 ep of rhythmic breathing lastng >30 sec w/in 30min
mvmt: >3 discrete limb mvmt w/in 30min
tone: >1 ep of extremity extension & subsequent return to flexion
AFV: AFP measuring >2cm in 1 planes perpendicular to each other 2x2cm pocket
further eval is not warranted regardless of BPS composite score if largest vertical AFP <2cm, T or F?
false
BPS score of 10 interpretation & mgmt
normal
no indication for intervention; repeat test weekly exc in DM & postterm px
BPS score of 8 (normal AFV) interpretation & mgmt
normal
no indication for intervention; repeat test weekly exc in DM & postterm px
BPS score of 8 (NST not done) interpretation & mgmt
normal
no indication for intervention; repeat test weekly exc in DM & postterm px
BPS score of 8 (dec AFV) interpretation & mgmt
chronic fetal asphyxia suspected
deliver
BPS score of 6 interpretation & mgmt
possible fetal asphyxia
AFV abnormal: deliver
normal fluid at >36 wks w/ favorable cervix: deliver
repeat test <6: deliver
repeat test >6: observe & repeat per protocol
BPS score of 4 interpretation & mgmt
probable fetal asphyxia
repeat testing same day; repeat test <6: deliver
>32 wks: deliver
BPS score of 0-2 interpretation & mgmt
deliver
what is the modified BPS?
vibro acoustic NST was performed 2x weekly w/ AFI determination (<5cm was considered abnormal)
ACOG reccom for diagnosing oligohyramnios, AFI or deepest vertical pocket?
deepest vertical pocket
doppler velocimetry, what are the vessels evaluated for growth restricted fetuses
UMA
MCA
DV
UMA mirrors what circulation?
downstream resistance of placental circulation
normal EDF
1/3 of systole
AEDV
umbilical artery resistance rises, diastolic velocity falls then become absent
REDV
further rise in resistance causing insufficient, rigid placental circulation recoils after being distended by pulse pressure
may precede fetal death by only hours to days
most significant prognostic feature in fetal growth restriction & placental insufficiency
EDF
> 34 wks w/ persistent AEDV interpretation & mgmt
uteroplacental insufficiency
deliver
<34 wks w/ persistent AEDV mgmt
individualized mgmt
REDV, BPS normal, AFI adequate, no decels on NST, normal venous doppler, approach?
antenatal steroids before delivery
MCA ideal location for doppler assessment
2mm from its origin from the internal carotid
clinical significance of MCA
detect several fetal anemia (MCA peak systolic velocity)
brain sparing hypoxia (reduce cerebrovascular impedance, inc blood flow to MCA)
cardiac decompensation (normalization, MCA diastolic falls returning to high resistance patter)
differentiate MCA flow in anemic fetus from brain-sparing hypoxia)
Anemic: inc waveform
Brain-sparing: dec waveform
doppler vessel, what is the best predictor of perinatal outcome?
ductus venosus
clinical significance of DV
triphasic blood flow pattern reflecting pressure changes w/in right heart d/t no intervening valvular structures
fetal demise w/in 1 wk (absent or reversed flow during atrial systole)
DV: absent a-wave interpretation
abnormal late-diastolic filling
DV: reversed a-wave interpretation
abnormal late-diastolic filling
DV: dec v-wave & D-wave, reversed a-wave interpretation
abnormal end-systolic (v) and holo-systolic (D, a) filling
DV: “M-shape”, dec v-wave, absent a-wave interpretation
abnormal end-systolic (v) and late-diastolic (a) filling
DV: dec v-wave & D-wave interpretation
abnormal end-systolic (v) and early-diastolic (D) filling
clinical significance of UtA
reflects impedance in utero-placental circulation
predict devt of preeclampsia & IUGR (16-18 wks)
what is the abnormal finding in UtA doppler?
end diastolic notch
REDV mgmt if >32 wks
antenatal steroids before delivery
IUGR & inc S/D ratio >95% mgmt
deliver at 37 wks
uncomlicated, isolated oligohydramnios mgmt
deliver at 36-37 wks
uncomlicated, isolated oligohydramnios at <36 wks mgmt
do follow-ups
recomm growth sacn in IUGR is every?
3-4 wks
