Intrapartum Fetal Surveillance Flashcards
Intrapartum Surveillance
* Fetal surveillance identifies fetal well-being or compromise
* Use surveillance to assess & then intervene to prevent any complications in the fetus
Fetal Oxygenation
* Using monitoring to identify issues of oxygenation during pregnancy & labor
- Surveillance will not detect every compromised fetus
What is required for fetal oxygenation?
* Normal maternal blood flow & volume to the placenta
* Normal oxygen saturation of maternal blood
* Adequate exchange of oxygen & carbon dioxide in the placenta (narrowing of spiral arteries can interrupt this)
* An open circulatory path between the placenta & fetus through vessels in the umbilical cord (into intervillous space & travels through umbilical cord to reach fetus)
* Normal fetal circulatory - oxygen-carrying functions
Pathologic Influences on Fetal Oxygenation
* Maternal cardiopulmonary alterations
* Uterine activity
* Placental disruptions
* Interruptions in umbilical blood flow
* Fetal alterations
Maternal cardiopulmonary alterations
* Hemorrhage
* Has an epidural (these cause vasodilation → feels hypotensive → dizzy)
* If has HTN (causes narrowing of spiral arteries)
* If has a maternal acid-base imbalance
Uterine activity
?
Contractions that are too long (>90-120 sec), too frequent (closer than every 2 min) or do not give enough of a relaxation period (at least 60 sec)
If receiving synthetic oxytocin = longer
tachysystole
With tachysystole is not allowing good utero-placental exchange to occur
* Can happen w/prostaglandin administration (we give these to ripen the cervix & prepare it for labor)
- Tachysystole can occur spontaneously
Placental disruptions
Abruptio placentae aka placental abruption
Placenta detaches from uterus prematurely
Bleeding out into abdomen from both sides (mom & baby)
?
Are areas of necrosis that can be in varying amounts on placental tissue
placental infarcts
Interruptions in umbilical blood flow
* Cord compression
Nuchal cord - wrapped around the neck or between the pelvis & presenting part
- Knot in the cord
- Cord is short
- Oligohydramnios
- Baby grabs & squeezes own cord
Fetal alterations
* Low fetal blood volume
* Fetal hypotension, anemia
* Cardiac issues like heart block
* A prolonged period of bradycardia or tachycardia can also impact fetal oxygenation
Determining Proper Fetal Monitoring
___ is 1 of the best signs of measuring fetal oxygenation
Fetoscope / Doppler / EFM
Variability
Fetoscope (less common nowadays)
Baseline Rate - Yes/No (?)
Variability - Yes/No (?)
Accelerations - Increases heard/absent (?)
Decelerations - Decreases heard/absent (?)
Rhythm - Yes/No (?)
Half Count/Double Count - Discerns/cannot discern differences (?)
Differentiate maternal & fetal heart rates - Yes/No (?)
* Yes
* No
* Increases heard
* Decreases heard
* Yes
* Discerns differences
* Yes [check mom’s pulse while listening to baby’s HR]
Doppler (handheld)
Baseline Rate - Yes/No (?)
Variability - Yes/No (?)
Accelerations - Increases heard/absent (?)
Decelerations - Decreases heard/absent (?)
Rhythm - Yes/No (?)
Half Count/Double Count - Discerns/cannot discern differences (?)
Differentiate maternal & fetal heart rates - Yes/No (?)
* Yes
* No
* Increases heard
* Decreases heard
* Yes
* Possible half/double count
* May detect maternal heart rate [could be inaccurate; might pick up maternal HR & we think it’s baby’s]
EFM
Baseline Rate - Yes/No (?)
Variability - Yes/No (?)
Accelerations - Increases heard/absent (?)
Decelerations - Decreases heard/absent (?)
Rhythm - Yes/No (?)
Half Count/Double Count - Discerns/cannot discern differences (?)
Differentiate maternal & fetal heart rates - Yes/No (?)
* Yes
* Yes
* Yes
* Yes
* Identifies type of deceleration
* Possible half count/double count
* May detect & record maternal HR
Fetoscope & handheld doppler used for ___ ?
* These provide mobility
We can’t view fetal tolerance of the labor
Can be disruptive, uncomfortable; needs a 1:1 ratio
intermittent auscultation
* Would not be able to do in a high-risk case; that needs continuous monitoring
The best place for auscultation is ___ ?
Leopold’s maneuvers are helpful here to determine fetal placement
* Ask mother about exams & where she’s felt the baby kick
over the fetal back
Auscultation Interpretation [using fetoscope & handheld doppler]
Category II (___)
Abnormal FHR baseline (tachycardia or bradycardia) OR
Irregular ___ OR
Presence of FHR decreases from ___
Nonreassuring
rhythm
baseline
Auscultation Interpretation
Category I (___)
Normal range FHR baseline (?)
AND
Regular rhythm
AND
Absence of FHR decreases from baseline
AND
FHR increases may or may not be present
Reassuring
110-160
Palpating Contractions
* Can time start to finish for duration
* Make observations for frequency
* Palpate uterus for intensity
> mild (tip of the nose)
> moderate (chin)
> strong (forehead, firm)
Electronic Fetal Monitoring
110/120 - 150/160 = Normal
* Can be intermittent; in facilities → continuous monitoring
* May limit mobility
* Requires adjustment of devices as mom and/or baby moves
* Can be difficult to trace either baby or contractions in moms who have larger amount of abdominal fat
* Need an internal device to accurately assess intensity
Upper grid - fetal HR (beats/min)
Lower grid - uterine activity (mm Hg)
EFM bedside unit
* Can monitor 2 babies
* Monitor mom’s contraction pattern, EKG, O2 sat, & BP
* Can have an internal device for baby & get fetal EKG
Portable unit
* Good for high-risk patients
US transducer / tocodynamometer aka a “toco” device
* US transducer can pick up fetal HR
* Both are used & needed w/continuous EFM
* Devices need to be against the skin
* toco should be placed at the fundus
* Transducer placed below the umbilicus on the abdomen
Internal devices that connect to monitors (accurate but invasive) - Fetal scalp electrode
* Can give an accurate fetal HR
* Membranes need to be broken in order to apply this to the fetal head
! Risk of infection
* Displaces easily
* Can pick up maternal HR (from mother’s cervix)
Intrauterine pressure catheter (IUPC)
* Has a pressure-sensitive tip that picks up the actual amount of pressure in the uterus
* Will tell us what the intensity is but we can also palpate the fundus to ascertain the intensity
Evaluating Electronic Fetal Monitor Strips
The Display
Baseline
___ to ___ bpm is a normal FHR baseline
For preterm is ___ to ___ bpm
* Look at when uterus is at rest versus contracting
110-160
140-160
Bradycardia
< 110 bpm
* Needs to be < 110 bpm & last for at least 10 min
* If < 10 min, termed a prolonged deceleration (a prolonged drop in the FHR)
* To be an actual change in baseline to bradycardia, it needs to occur 10 min or more
Tachycardia
Baseline > 160 bpm
* Needs to be > 160 bpm for at least 10 min
If < 10 min, termed a prolonged acceleration (a prolonged increase in HR but considered temporary)
* 10 min or more is considered a change in baseline & that is a true tachycardia
Can be due to infection, in response to dehydration or maternal rx’s
Moderate variability
___ to ___ bpm variation around baseline
6-25 bpm
Minimal variability
< ___ bpm variation around baseline
< 5 bpm
Marked variability
> ___ bpm variation around baseline
* With marked variability, you really can’t distinguish what the baseline is
* Is too much fluctuation from beat to beat to measure appropriately
* Do not like to see this
25 bpm
Fetal Accelerations & Decelerations - “VEAL CHOP”
V = C
E = H
A = O
L = P
Variable deceleration = Cord compression
Early deceleration = Head compression
Acceleration = Okay (or oxygenation)
Late deceleration = Placental insufficiency
Variable Deceleration
Abrupt onset of nadir < ___ sec with drop of 15 bpm below baseline for ≥ 15 sec but < 2 min in duration
* Relationship to the contraction is variable
* Onset to nadir < ___ sec
30
30
* The umbilical vein is what’s supplying oxygenated blood to the fetus
* The vein is the 1st to collapse
* Is the only type of deceleration in which you see the fetal HR increase before & after
Early Deceleration
Nadir of decel matches ___ of contraction
Is onset to nadir > or < 30 sec ?
peak
> (greater than) 30 sec
Acceleration
Acme of 15 bpm above baseline with duration > 15 sec but < 2 min
* Is an increase from the baseline of 15 bpm that lasts at least 15 sec but less than 2 min
* If we go over 2 min that changes it into a prolonged acceleration
Accelerations reinforce good oxygenation; shown in response to fetal movement
Prior to 32 weeks gestation expect a 10x10 rather than a 15x15
If less than 28 weeks gestation, no accelerations present d/t immaturity of ANS
___ Deceleration
Onset, nadir, & recovery of decel follow beginning, peak, & end of contraction
Onset to nadir > 30 sec
Nadir often occurs after peaks of contraction
* Concerning if they occur w/more than 50% of the contractions
Late
* Late decelerations are a sign of placental insufficiency = bad
Prolonged Deceleration
Decel is ≥ 15 bpm and > 2 min but < 10 min
Sinusoidal Pattern
* Are associated w/high rates of fetal morbidity & mortality
* From severe anemia, narcotic use, severe fetal asphyxia or hypoxia, fetal infections, cardiac anomalies
* Sawtooth, waveform pattern
* Can see a pseudo-sinusoidal pattern - “false” d/t baby thumb-sucking
> Pattern will break
* Are a Category III fetal HR pattern; moving towards C-section
Contractions: External Toco
* Frequency
* Duration
* Intensity
> mild, moderate, or strong?
* Resting tone (time between contractions; nothing happening; time where fetal oxygenation is happening)
