Fetal Assessment
in labor
Objectives
• Compare fetal heart rate monitoring done by intermittent
auscultation and external and internal electronic methods.
• Explain baseline fetal heart rate.
• Identify reassuring fetal heart rate patterns.
• Describe preventative measures that can be used to
maintain fetal heart rate patterns within normal limits.
• Understand the concepts of timing, frequency, duration,
terminology and physiology of uterine contractions.
• Identify signs of non-reassuring fetal heart rate patterns,
describe nursing interventions used for the management of
specific fetal heart rate patterns, and discuss the etiology
and rationale.
During
labor the fetus can be deprived of
oxygen. How the infant tolerates this must
be monitored.
Electronic Fetal Monitoring (EFM)
• External
– Ultrasound transducer
– Tocotransducer
• Internal
– Spiral electrode
– Uterine catheter
Fetal Heart Rate
Controlled by autonomic nervous system
• Sympathetic increases FHR
• Parasympathetic decreases FHR
Baseline fetal heart rate
Average rate during 10 minute segment
110 – 160 beats per minute
130
120
Tachycardia
– >160
– Early sign of fetal hypoxia
– Increased maternal temperature
– PPROM
– drugs
190
170
150
Bradycardia
– <110
– Later sign of fetal hypoxia
– Decreased maternal blood pressure
– Prolonged umbilical cord compression
– terminal
100
80
60
FHR Baseline Characteristic

Variability of FHR
–
Increased: early, mild sign of hypoxia and
fetal stimulation
–
Decreased: sleep state, hypoxia, acidosis,
CNS depressant medications (ominous if
caused by hypoxia or associated with late
decelerations)
130
120
Baseline fetal heart rate
• Variability
– Irregular fluctuations in FHR baseline
– Rythmic wave cycles
Characteristics of reassuring fetal heart rate
(FHR) pattern
FHR between 110-160
Normal baseline variability
Absence of non-reassuring changes
(decelerations)
• Accelerations of FHR with Fetal movement
Other Fetal Heart Rate Changes
Accelerations
occur spontaneously and with
fetal movement and indicate fetal well-being.
FHR Accelerations
15bpm

15bpm
Characteristics of Normal Uterine
Activity
• Contractions every 2 to 5 minutes
• Duration of contractions less than 90 seconds
• Intensity of contractions less than 100 mm Hg
pressure
• 60 seconds or more from end of one contraction to
beginning of another
• intrauterine pressure of 15 mm Hg or less between
contractions
Early Decelerations
Late decelerations
Variable Decelerations
Factors associated with reduction of fetal oxygen
supply
Reduction of blood flow through maternal vessels
ctxs, BP, BP, hypovolemia
• Reduction of oxygen content in maternal blood
– Hemorrhage, severe anemia
• Alteration in fetal circulation
– Cord compression – transient, prolonged
– Placenta separation, head compression (ICP and vagal nerve
stimulation  FHR
• Reduction of blood flow to intervillous space in placenta
– calcifications
Non-reassuring fetal heart rate patterns
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Progressive  or  in baseline
Tachycardia
Decrease in baseline variability, loss of variability
Severe variable decelerations
Late decelerations
Prolonged deceleration
Severe bradycardia
Nursing actions when non-reassuring FHR
pattern occurs
• Change mom’s position
– Increase perfusion
• Correct maternal hypotension
– Position, fluids, drugs
• Elevate hips
– Increase blood return
• Increase rate of IV
– Increase circulating volume
• Discontinue oxytocin, if infusing
– Possibly give tocolytics
• Administer oxygen at 10 liters minute via face mask
– Firm, tight fitting face mask
Non-reassuring FHR
• Prepare for emergency delivery if pattern
cannot be corrected
Assessment of Fetal Well-being
• Scalp Stimulation
• Vibroacoustic
• http://utilis.net/fhm/2405.htm