Antepartum Assessment Flashcards
(47 cards)
When/why is the first ultrasound in pregnancy?
7 wks- confirm pregnancy, exclude ectopic or molar pregnancy, confirm cardiac pulsation, crown-rump length (dating)
When/why is second ultrasound in pregnancy?
18-20 wks
Look for congenital malformations, verify dates/growth, placental position
When/why is third ultrasound in pregnancy?
34 wks
Evaluate fetal size, assess fetal growth, verify fetal position
What/when can you see on early ultrasounds?
4.5 wks- gestational sac 5 wks- yolk sac 5.5 wks- embryo 6-7 wks- heartbeat and blood flow 7-13 wks- crown-rump length 13 wks- biparietal diameter 14 wks- femur length
What measurements are used for dating/ how accurate are they?
CRL (early first tri) +/- 4.7 days
BPD/HC/AC/FL up to 22 wks +/- 1wk
^ up to 30 wks +/- 2wks
After 30 wks +/- 2-3wks
When are EFW and growth scans done?
If fundal ht lags/exceeds EGA by EDD
*accuracy is low
HC/AC ratio is good predictor for IUFGR
What is the only caution with ultrasound?
Can increase body temperature
Significant only for long exposure time
When is a NST considered reactive?
2 access in 20 minute period, 40 minute max testing, plus normal baseline and moderate variability
What do you need to know about vibroacoustic stimulation?
Sound stimulus applied for 3 seconds
Reactive accel correlates with nonacedemic fetus
Decreased effect in preterm or once ruptured
What do you need to know about scalp stim?
Rule out metabolic acidemia Not to fontanels Done between contractions Accel good predictor of non-acidemic Lack of accel poor predictor of acidemic
What do you do if you get a non reactive NST?
BPP or CST
What is a CST?
3 ctx in 10 minutes with oxytocin or nipple stim
What are the possible results of CST?
Negative- no late decels
Positive- recurrent lates
Suspicious- intermittent lates or variables
Unsatisfactory- poor tracing or not 3 ctx
What do you do if you get a nonreactive negative CST?
Repeat in 24 hrs
What do you do if you get a positive CST?
BPP, consider delivery
What do you do if you get a suspicious or unsatisfactory CST?
Repeat in 24 hrs
What are the components of a BPP/ when do they develop?
Fetal tone (7-8wks) Fetal movement (9wks) Fetal breathing movements (20-21wks) Reactive NST (28-32wks) Qualitative AFV
What is a score of 2 for fetal breathing movements in a BPP?
1 or more episodes >30 seconds within 30 minutes
What is a score of 2 for gross body movements in a BPP?
3 or more limb/body movements within 30 minutes
What is a score of 2 for fetal tone in a BPP?
1 or more episodes of extension/return to flexion of limbs or trunk (or open/close of hands)
What is a score of two for qualitative AFV in a BPP?
1 or more pockets of fluid measure 2 or more cm
What is each parameter of a BPP regulated by?
CNS
first to appear, last to disappear with fetal asphyxia
How does ultrasonography work/ what is it used for?
Used by sound waves
Used to date, anatomy of fetus, examine placenta and amniotic fluid
Also used to assist in procedures (ie amnio)
What is the interpretation/follow up for a BPP score of 8 or 10?
Normal, low risk for chronic asphyxia
Repeat weekly or 2x/wk
