1.03 Antepartum Fetal Surveillance Flashcards
Primary goal of Fetal Surveillance
Prevent Intrauterine Fetal Death
What happens before IUFD?
fetal acidosis and hypoxemia
Summary of steps leading to IUFD
Fetal acidosis and fetal hypoxemia > amniotic fluid, fetal movement, and fetal heart rate changes > IUFD > still birth
Clinical Assessment methods for fetal surveillance
Determination of fetal age
Fundic Height
Fetal Heart Tones
Once the fetal pole can be visualized, this is the most accurate method for dating the pregnancy
Crown-Rump Length
The fundic height in cm is equal to AOG in these weeks
20-32 weeks with a margin of +/-2
Ways to calculate fetal age
LNMP
Fundic Height
Ultrasound Measurement
T/F: Fetal heart tones can be heard at 8 weeks
Normal range of heart sounds:
F- 12-13
120-170 bpm
T/F: Fetal death within one week of a normal test is common
F- rare
T/F: Fetal movements commence as early as 7 days
At what week/s does the fetus start to become organized and start to show rest-activity cycles?
F- 7 weeks
20-30 weeks AOG - reflective of CNS development and maturation
At what behavioral state is a fetus in when they are at quiet sleep?
State 1F
At what behavioral state is a fetus in when they have continuous eye movements, absence of body movements, and minimal variability of heart rate
Stage 3F
At what behavioral state is a fetus in when they have vigorous body movement with continuous eye movement and heart rate accelerations
State 4F (awake)
T/F: Contraction stress test assesses uteroplacental function that is done in early pregnancy
F- latter part of pregnancy
At what behavioral state is a fetus in when they have continuous eye movements, gross body movements, and increased variability of heart rate
State 2F (REM SLEEP)
State if these (increases/decreases) fetal movement
Maternal smoking
Steroid administration up to 72 hours
Glucose load
Sedatives
Fetal positioning (anterior spine)
Maternal smoking - decreased
Steroid administration up to 72 hours - decreased
Glucose load - increased
Sedatives - decreased
Fetal positioning (anterior spine) - decreased
What must be done to evaluate decreased fetal movement?
Non-stress test and amniotic fluid volume
T/F: reduced/absent movement is a sign of impending fetal death
The mother must start to monitor fetal movement starting at what week/s?
How many kicks must be felt?
T
Starting 26-28 weeks
at least 10 kicks in 2 hrs and mother’s subjective impression
How does contraction test work?
T/F: The CST can only be done in a double set up
The baby is intentionally stressed through contractions by:
Mom’s given contractions via nipple stimulation OR Oxytocin therapy (10 units titrated at 6mU/min > at least 3 contractions lasting 40s or longer is needed in a 10 min span > there is brief periods of impaired oxygen exchange > a normal healthy fetus can cope up to 1 minute oxygen impairment while unhealthy fetuses cant
T
This is the most important predictor of adequate fetal oxygenation
Variability
When is acceleration considered?
When is deceleration considered?
T/F: Decelerations are compensatory mechanisms for decreased oxygen
If there is an abrupt increase of bHR of >15 bpm for >15 seconds >32 weeks
If there is an abrupt decrease of bHR of >15 bpm for >15 seconds if >32 weeks
If <32 weeks, change of 10bpm within >10 seconds
T
Identify the type of variability
6-25 bpm
>25 bpm
1-5 bpm
0 bpm
Which among the types of variability indicate presence of accelerations? No apparent baseline?
6-25 bpm = moderate
>25 bpm = marked
1-5 bpm = minimal
0 bpm = absent
W/ Accelerations = moderate
No apparent baseline = marked
This type of deceleration starts at the same time as the contractions
This happens secondary to ________
Early
secondary to head compressions
When do late contractions start?
This happens secondary to ________
T/F: Late contractions are the most worrisome
After the peak of contraction
Happens due to uteroplacental insufficiency
T