OB Module 4: Fetal Surveillance Flashcards
What are the two patients we truly take care of in OB
mother
child
What tests are included under Ante Partum Fetal Surveillance
Fetal Movement Assessment
Nonstress Test
Contract Stress Test
BPP (Biophysical Profile)
Umbilical Artery Doppler Velocimetry (done via ultrasound)
Ultrasound
Amniocentesis
Chorionic Villi Sampling
What are some maternal conditions that may warrant fetal surveillance
Antiphospholipid syndrome
Hyperthyroidism (poorly controlled)
Hemoglobinopathies (hemoglobin SS, Sc, or S-thalassemia)
Cyanotic heart disease
Systemic lupus erythematosus
Chronic renal disease
Type 1 diabetes mellitus
Hypertensive disorders
What are some pregnancy related conditions that may warrant fetal surveillance
Pregnancy-induced hypertension
Decreased fetal movement
Oligohydramnios
Polyhydramnios
Intrauterine growth restriction
Postterm pregnancy
Isoimmunization (moderate to severe)
Fetal anomalies
Previous fetal demise (unexplained or recurrent risk)
Multiple gestation (especially with significant growth discrepancy)
Oligohydramnios
Low amount of amniotic fluid
Polyhydramnios
High amount of amniotic fluid
Isoimmunization
rH incompatabilities
What test is the lowest level of fetal surveillance
Fetal Movement Assessment
AKA: Fetal Kick Counts
What is done in a Fetal Movement Assessment
the mother counts the fetal “kicks” as a means of antepartum fetal surveillance
When should a fetal kick count be done
after dinner with the mother resting on her side ideally
it is done for up to 2 hours then or anytime the baby tends to kick
A mother should not do what within 2 hours prior to a fetal movement assessment
smoke d/t diminished oxygen flow
What are the ideal results for a fetal movement assessment
She should have at least 10 movements in a 2 hour period
if she feels that before 2 hours are up she is done and set to go
What is important to keep in mind about the timeline of a fetal movement assessment
infants can sleep up to 45 minutes so that may be why there is no kicking
Advantages of the Fetal movement assessment
low tech
done as a daily assessment
can be done on all pregnancies
reassuring for the mother
Major disadvantage of the fetal movement assessment?
it is done at a very busy time of day
What are some methods of electronic fetal monitoring?
External monitoring
internal fetal monitoring
IUPC - intrauterine pressure catheter
What is the basic way electronic fetal monitoring works
Two belts go on mother
top one monitors contractions - toco transducer- detects tone in the abdomen that detects contraction (it is on top since the contraction pulls up)
the lower one detects fetal heart tones assuming the baby is in a normal spot
the lowest are optimal anterior
How does an internal fetal monitor to check the scalp work?
to get the internal monitor in the cervix must be dilated, membranes ruptured, and you need to be able to palpate the bony prominences of the infant (not placing it on the fontanelle or something else)
What are the three important parts of EFM (electronic fetal monitoring) interpretation>
- Baseline (For FHR)
- Variability (Jaggedness to Lines)
- Periodic Changes (Increases and Decreases)
How are FHR electronic monitoring results categorized?
It is a three tier system with 3 categories
Category I - Normal
Category II - Suspicious
Category III - Ominous
EFM: Variability
reflects the health of the nervous system, chemoreceptors, baroreceptors, and cardiac responsiveness
What is Variability indicative of in EFM
the health of the parasympathetic nervous system (is it intact, oxygenated, functional) if it is 5-10 bpm above baseline
the health of the sympathetic nervous system if it is 10-25 bpm off the baseline
How many BPM off the baseline of a FHR is indicative of the health of the PNS
5 to 10 bpm
How many BPM off the baseline of an FHR is indicative of the health of the SNS
10 to 25 bpm
What is acceleration of the EFM
an increase in amplitude of 10-25 bpm off the baseline indicative of the health of the SNS
should only occur once in a while
What does the fetal heart rate snapshot about a child?
how they are doing and what is happening neurologically
What does prematurity do to EFM variability
it decreases variability so there will be little rate fluctuation before 28 weeks!
When should variability in EFM be present
after 32 weeks
What, other than prematurity can decrease EFM variability
fetal hypoxia
congenital heart anomalies
fetal tachycardia
systemic pain medications - temporarily
fetal metabolic acidosis
CNS depressants
fetal sleep cycles
preexisting neurological abnormalities
betamethasone
Why is there little fluctuation in FHR/EFM before 28 weeks
because the neurological system must be developed enough to allow and spot changes
What are the variability changes (amplitude/BPM) in EFM for the following:
Absent
Minimal
Moderate
Marked
Absent - amplitude range undetectable
Minimal = <5 BPM
Moderate - 6-25 BPM
Marked- >25 BPM
What appears to be the most significant intrapartum sign of fetal compromise?
Persistently minimal or absent FHR variability
While persistently low variability is an ominous sign…
the presence of good FHR variability may not always be predictive of a good outcome
Betamethasone
a drug given to accelerate infant lung maturity
can decrease EFM variability though
What is important to keep in line about looking at the variability of a monitor?
it is always slightly exaggerated so with something like absence it is even worse than it appears!
What may cause some temporary drops and declines in variability?
movement where the babies heart rate is outside the detection of the monitor
What is the normal baseline for FHR
120-160 BPM
Often this is on the high end for prematurity
they tend to be within 140-160 or 130-250 area
Fetal bradycardia
baseline HR <120 BPM
If 100-120 BPM with normal variability it is not associated with fetal acidosis
What are some etiologies for Fetal bradycardia
heart block (if little or no variability)
occiput posterior or transverse position
serious fetal compromise
if the neurological system is maturing and the baby goes post date then it is common to go low as well
Why does a premature baby tend to have a faster heart beat
because the neurological and cardiac systems are less mature and not coming down as easy
Fetal Tachycardia
fetal baseline HR >160 BPM
Fetal Tachycardia is considered a ___ pattern
nonreassuring (ominous)
When is Fetal Tachycardia considered mild? severe?
Between 160-180 BPM for mild; >180 BPM for severe
Why might a fetus have a HR of >200 BPM?
it is usually fetal tachycardia due to fetal tachyarrhythmia or a congenital anomaly rather than hypoxia
Persistent Fetal Tachycardia
a consistent >180 BPM HR that often occurs in conjunction with fetal hypoxia, fetal anemia, and maternal fever
What does persistent fetal tachycardia with fetal hypoxia, fetal anemia, or maternal fever suggest?
Chorioamnionitis - infection of the uterus
May have occurred if the cervix dilated and bacteria went up
Category I Fetal heart Rate Tracing
“Normal” FHR Showing All of the Following:
Baseline FHR 110-160 BPM
Moderate Variability
Accelerations Present or Absent
No Late or Variable Decelerations
May Have Early Decelerations
What is a Category I Tracing predictive of?
Normal Acid Base Status at the time of observation and typical routine care to be done
Category II Fetal Heart Rate Tracing
A FHR tracing showing any of the following: (Drops in baseline and variability changes)
Tachycardia
Bradycardia w/out Absent Variability
Minimal Variability
Absent Variability w/out Recurrent Decelerations
Marked Variability
Absence of Accelerations After Stimulation
Recurrent Variable Decelerations w/ Min/Mod Varia.
Prolonged Decelerations >= 2 min but less than 10min
Recurrent :ate Decelerations w/ Moderate Variability
Variable Decelerations w/ Other Characteristics such as slow return to baseline and “overshoot”
What is Category II FHR Tracings NOT Predictive of?
Abnormal Fetal Acid Base Status
BUT it does require continued surveillance and reevaluation
Category III FHR Tracing
Fetal Heart Tracing Showing EITHER of the following:
- Sinusoidal Pattern
OR
- Absent Variability w/ Recurrent Late Decelerations, Recurrent Variable Decelerations, or Bradycardia
What is Category III FHR Tracings Predictive Of?
Abnormal fetal Acid base status at the time of observation
Depending on the clinical situation, efforts to expeditiously resolve the underlying cause of the abnormal FHR should be made - such as rapid induced delivery
Sinusoidal Pattern
an abnormal category III FHR pattern
also called “Saw Tooth” pattern with it very equal going up and down
indicative of fetal hypoxia from anemia or O2 disruption
Periodic FHR tracing changes include both __ and __
accelerations and decelerations
What sort of pattern do we want to see on an FHR tracing, and what could hypothetically sometimes happen?
We want to see baseline range with some jaggedness that changes giving variability - hopefully that variability is an acceleration in HR
Sometimes we get decelerations but we must consider what they occur in relation to - if a contraction just occurred then we know some squeezing temporarily cut off O2 and would lead to that
Decelerations on FHR Tracings are Classified as…
Early
Variable
Late
Prolonged
Early Decelerations are due to …
head compression
Early and Late Decelerations tend to have what shape
A Subtle U shape
Variable Decelerations tend to have what shape
A Very Deep V or W shape
Why is head compression so important to know about with FHR tracings?
Head compression is a mirror image of contraction rate and depending on compression severity or duration we may lose variability gradually if the baby cannot make it thought
We may see this coming as the head makes it through the ischial spine region
Why are late decelerations in FHR so concerning
they are an ominous sign of placental insufficiency (inadequate blood flow)
as the uterus contracts, placental blood flow will cut off and if the placenta is already compromised there is even worse blood flow compromise
How can induction of labor cause late decelerations in FHR?
Never sure how responsive the uterus will be so we can cause severe and strong contractions without much of a rest period in between
When occurring progressively less blood flow will get to the baby and cause late decelerations
When will late decelerations begin and end in reference to contraction?
It will start toward the peak of contraction and will recover at the end of a contraction
What causes variable deceleration
Cord Compression - and depending on where the cord is this may or may not occur with contractions
When will variable decelerations correspond with contractions?
If the cord is around the shoulder or neck
OR
With specific maternal positions that move the cord