Intrapartum Fetal
Surveillance
Fetal Oxygenation
Placental Physiology

Maternal blood flows through the uterine
arteries into the intervillous spaces
then
return through uterine veins to maternal
circulation

Fetal blood flows through the umbilical arteries
into the villous capillaries and returns through
the umbilical vein to fetal circulation.

Exchange of blood gases depends on an
unobstructed blood flow through the placenta.
Uteroplacental exchange

As the myometrium contracts, the
flow of oxygenated blood through
the uterine artery may be
decreased.

Therefore, the fetus may have less
oxygen available.
Regulation of Fetal Heart Rate
Autonomic nervous system
 Baroreceptors
 Chemoreceptors
 Adrenal Gland
 Central Nervous System

Electronic Fetal Monitoring
Standard of Care

“Nurses who care for women during
the childbirth process are legally
responsible for correctly
interpreting FHR patterns, initiating
appropriate nursing interventions
based on the pattern seen, and
documenting the outcome of those
interventions.”
Indications for Electronic Fetal
Monitoring

Previous history of stillbirth

Complications of pregnancy

Induction of Labor

Preterm labor

Nonreassuring fetal status;

Meconium staining of amniotic fluid
fetal movement
Advantages of EFM

Constant sound of FHR is reassuring and
comforting to the family

Supplies more data about the fetus and
gradual trends in FHR are more apparent

Coach uses strip pattern tracing to assist with
support
Disadvantages of EFM

Reduces patient’s mobility

Requires repositioning of equipment
with fetal or maternal movement

Can impart a technical air to the birth
process
Methods of Fetal Monitoring
Intermittent ausculation by
doppler
Continuous external
monitoring
Continuous internal
monitoring
Auscultation by Doppler

Intermittent auscultation can be done with a
Fetascope
or
Doppler
for FHT’s

External Monitoring
The tocodynamometer
(“toco”) is placed over
the uterine fundus. The
toco provides
information that can be
used to monitor uterine
contractions.
The ultrasound
device is placed
over the area of
the fetal back.
This device
transmits
information
about the FHR.
Information from both the toco and the ultrasound device is
transmitted to the electronic fetal monitor.
The FHR is displayed in a digital display (as a blinking light), on
the special monitor paper, and audibly (by adjusting a button on
the monitor). The uterine contractions are displayed on the
special monitor paper as well.
Internal Monitoring
Criteria for Internal Monitoring:
 Amniotic membranes must be ruptured
 Cervix dilated 2 cm.
 Presenting part down against the
cervix
Spiral Electrode is placed on the fetal
occiput which allows for more accurate
continuous data then external monitoring.
Also is not affected by mom or fetal
movement as with external monitoring.
Internal Monitoring
The spiral electrode is
attached to the
fetal scalp
Wires that extend
from attached spiral
electrode are attached
to a leg plate and then
attached to electronic
fetal monitor.
Nursing Responsibilities
Electronic Fetal Monitoring





Placement of equipment
Teaching the woman about use
Notation of events on the strip
Evaluation of data
Intervention as indicated by data
Baseline Fetal Heartrate
Normal Pattern

Baseline FHR = 120 – 160 bpm
Patterns

Tachycardia – baseline above 160 BPM
– RT= maternal fever, fetal hypoxia,
intrauterine infection, drugs

Bradycardia – baseline below 110 BPM
– RT = profound hypoxia, anesthesia,
beta-adrenergic blocking drugs
Variability


Normal/ increased variability or irregularity of a cardiac
rhythm.
Absence or decreased variability, or a smooth
flat baseline, is a sign of fetal compromise.
Causes of Decreased Variability
Hypoxia and acidosis
Medications
Sleep cycle
Preterm status
Periodic changes in the FHR

Accelerations – increase in the
fetal heart rate with a return to
baseline.

Indication of fetal well-being is an
acceleration of 15 bpm for 15
seconds.
Reassuring Acceleration Pattern
Baseline fetal heart rate is 120-160 with preserved beat-to-beat variability.
Accelerations last for 15 or more seconds above baseline, and
peak to 15 or more bpm.
Periodic changes in the FHR
Decelerations

Early – related to head compressions.
Interventions not necessary

Variable – related to cord compression.
Interventions vary, but focus on position
changes.

Late – related to uteroplacental
insufficiency. Most ominous and need
immediate attention.
Early Deceleration
The onset and return of the deceleration coincide
with the start and end of the contraction.
Fetal Heart Rate
Contractions
Early Decelerations

Related to Head Compression

Intervention
– No intervention necessary. Just
continue to watch for any changes.
Variable Deceleration

Variable decelerations are variable in
duration, intensity, and timing
Variable Decelerations

Related to cord compression

Intervention
– Reposition
– Amnioinfusion
Late Deceleration

The fetal heart tones return to the
baseline AFTER end of contraction
Late Decelerations

Related to decreased uteroplacental
perfusion
Nursing Care for
FHR Decelerations

Stop the Pitocin

Reposition - Turn woman to a side-lying
position, or knee- chest position. Avoid supine
position

Increase rate of the mainline IV

Administer oxygen by mask at 10 L/min.

Give Terbutaline sub-q.
Nursing Care

Notify the primary care provider

If condition does not improve, then
prepare for immediate delivery
Fetal Scalp Stimulation

Gently stroke or massage fetal scalp for
15 sec. during a vaginal examination

Assess fetal tracing for signs of
accelerations of 15 bpm for 15 sec.

This is a sign of fetal well-being
Fetal Scalp Blood Sampling

Requires rupture of
membranes

Acidosis is present if
the pH is less
than 7.20
Cord Blood Analysis

Criteria
– Significant abnormal FHR
– Meconium stained amniotic fluid
– Infant is depressed at birth

Small amount of blood obtained from
umbilical cord and tested for acidosis
– Normal fetal blood pH should be >7.25
– Lower level indicate acidosis and hypoxia
Montevideo Units

Montevideo units is a measure of uterine
contraction intensity during labor.

Units are calculated via internal pressure
monitor, measuring uterine contraction peak
pressure and subtracting the baseline resting
tone. This is done over a 10 minute interval.

Generally, above 200 MVUs is considered
necessary for adequate labor to bring about
dilation and effacement during the active
phase.
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