3. • The primary objective of EFM is to provide information
about fetal oxygenation and prevent fetal injury that
could result from impaired fetal oxygenation during
labor.
• This is achieved by detecting fetal heart rate changes
early before they are prolonged and profound.
EFM
4. • Adequate fetal oxygenation requires five related factors:
• Adequate maternal blood flow and volume to the
placenta.
• Adequate oxygen saturation in maternal blood.
• Adequate exchange of oxygen and carbon dioxide in the
placenta.
• An open circulatory path between the placenta and the
fetus through vessels in the umbilical cord.
• Adequate fetal circulatory and oxygen-carrying
functions.
Fetal Oxygenation
5. • Review: Oxygen rich and nutrient rich blood from the
mother enters the intervillous spaces of the placenta
through the spiral arteries.
• Oxygen and nutrients in the maternal blood pass into the
fetal blood that circulates in capillaries in the intervillous
spaces.
• CO2 and other waste products pass from the fetal blood
into the maternal blood at the same time.
• Maternal blood carrying fetal waste products drains from
the intervillous spaces through endometrial veins and
returns to the mother’s circulation for elimination.
Uteroplacental
Exchange
6. • Substances pass back and forth between mother and fetus
without mixing of maternal and fetal blood if fetal
capillaries remain intact.
• During labor contractions gradually compress the spiral
arteries, temporarily stopping maternal blood flow into
the intervillous spaces.
• Thus during contractions the fetus depends on the oxygen
supply already present in body cells, along with
intervillous spaces. Oxygen supply in these areas is
enough for about 1 to2 minutes.
Exchange continued:
7. • The average heart rate measured over a 2 minute period
within a 10 minute window
• Normal=110-160
• Brady=<110 for 10 minutes
• Tachy=>160 for 10 minutes
• Pre-term may have >160 due to immature
parasympathetic NS
Baseline FHR
8. • Most important component of the FHR
• Irregular fluctuations in the baseline fetal heart rate.
• Measured as the amplitude of the peak to trough in bpm
• Evaluates fetal autonomic nervous system, adequate 02
status promotes normal FX
• Long-term variability(LTV) broader fluctuations of the
FHR
• Short-term variability(STV) beat-to-beat variability, only
with IFSE
• No variability=fetal compromise
Variability
13. • Accelerations (accels) – transitory abrupt increases in the
FHR above the baseline,15 bpm above baseline FHR
greater than 15 sec less than 2 minutes. Reassuring; thus
denoting fetal movement and fetal well-being and are the
basis for nonstress testing.
• Decelerations- transient fall in FHR caused by
stimulation of the parasympathetic NS.
• Early=head compression
• Late=utero-placental insufficiency
• Variable=cord compression
Periodic changes
15. • Deceleration with each contraction
• Mirror image when contraction begins
the heart rate begins to drop
• Action – prepare for birth
Head compression
17. • Deceleration with each contraction
• Late onset, usually see a decrease in variability
• Action=intra-uterine resuscitation
• If on Pitocin – turn it OFF
• Increase mainline fluid volume, bolus with LR
• O2 via face mask at 8-10 L
• Turn to left side, or whatever position best for blood flow
• Scalp stimulation?
Late decelerations
19. • Occurs randomly
• Not a problem if occasional and returns to baseline
• If frequent, long return, < variability=intrauterine
resuscitation.
• Turn to left side
• Pitocin off and increase fluids
• O2 via face mask at 8- 10 L
• Amnioinfusion – warm NS
Variable deceleration
20. Prolapsed cord
• Do not remove fingers
after exam
• Relieve pressure from
presenting part
• Call for help, prepare for
emergency C/S
• Remain calm
21.
22. • Reduced mobility
• May require frequent adjustment of equipment to obtain
continuous tracing
• Best identifies the well oxygenated fetus…does not
reliably identify the compromised fetus
• Increased operative intervention
EFM
Limitations
23. • Intra-uterine resuscitation
• Measures create anxiety, fear, and loss of control
• Remain calm, educate patient and family, and choose
words wisely
• Report all interventions to MD
Interventions
24. • Supplies more data, becomes part of the permanent
record
• Shows FHR in relation to stimuli
• Provides a feeling of safety for the parent
• Allows nurse/patient ratio to be 1:2 with central
monitoring
EFM
Advantages
