1. CARDIOTOCOGRAPHY

2. Methods of Monitoring The Fetal
Heart Rate:
(1) Fetal Stethoscope (Pinard) and Hand-Held
Doppler (Sonicaid)
(2) Cardiotocograph (CTG)

3. (1) Fetal Stethoscope (Pinard) and
Hand-Held Doppler:
• Intermittent monitoring can be undertaken either by
listening to:
1. the baby’s heart rate using a fetal stethoscope
(Pinard) - after French obstetrician Adolphe
Pinard or
2. a handheld doppler ultrasound device and
3. by palpating the mother’s uterine contractions by
hand. This is known as ’intermittent auscultation

4. (2) Cardiotocography (CTG)
• Cardiotocography (CTG) is a technical means of
recording (-graphy) the fetal heartbeat (cardio-) and the
uterine contractions (-toco-) during pregnancy, typically
in the third trimester.
• The machine used to perform the monitoring is called
a Cardiotocograph, more commonly known as an
Electronic Fetal Monitor (EFM).

6. Note
• The term Electronic Fetal Monitoring is sometimes
used instead of CTG monitoring, but is considered to
be a less precise term because :
1. CTG monitoring also includes monitoring the
mother’s contractions and
2. other forms of fetal monitoring might also be classed
as ‘electronic’ e.g. ECG, fetal pulse oximetry

7. Method
• Recordings are performed by TWO separate
transducers;
 one for the measurement of the fetal heart rate
and
 a second one for the uterine contractions.
• Each of the transducers may be either external or
internal.
1) External measurement means taping or
strapping the two sensors to the abdominal
wall. This is called an indirect measure

8. 2) Internal measurement ( direct ) requires a
certain degree of cervical dilatation,
 as it involves inserting a pressure catheter
into the uterine cavity, as well as attaching
a scalp electrode to the child's head to
adequately measure the electric activity
of the fetal heart.
 Internal measurement is more precise,
and might be preferable when a
complicated childbirth is expected.

9. Interpretation
• Includes description of:
1) Uterine activity (contractions)
2) Baseline fetal heart rate
3) Baseline FHR variability
4) Presence of accelerations
5) Periodic or episodic decelerations

10. 1) Uterine Contractions
• There are several factors used in assessing uterine
activity :
a) Frequency: the amount of time between the start of
one contraction to the start of the next contraction.
b) Duration: the amount of time from the start of a
contraction to the end of the same contraction. (e.g.
15 secs)
c) Intensity: a measure of how strong a contraction is.
(mild, moderate, strong)

11. Intensity
• With external monitoring, this necessitates
the use of palpation to determine relative
strength.
• With internal monitoring, this is determined
by assessing actual pressures as graphed on
the paper.

12. d) Resting Tone: a measure of how relaxed the uterus
is between contractions.
e) Interval: the amount of time between the end of
one contraction to the beginning of the next
contraction.

13. Uterine Activity
• May be defined as:
 Normal less than or equal to 5
contractions in 10 minutes.
 Tachysystole more than 5 contractions in
10 minutes .

14. 2) Baseline Fetal Heart Rate
• The average rate between peaks and
depressions over a period of time that doesn’t
include accelerations or decelerations of the
heart rate.
• The baseline fetal heart rate is the heart rate
range that occurs between uterine
contractions.
• The normal baseline heart rate can be
anywhere between 110 and 160 beats per
minute.

17. How Do Uterine Contractions Affect
Fetal Heart Rate?
• Uterine contractions can affect fetal heart rate by
increasing or decreasing that rate in association with
any given contraction.
• The THREE primary mechanisms by which uterine
contractions can cause a decrease in fetal heart rate
are compression of:
o Fetal head
o Umbilical cord
o Uterine myometrial vessels

18. • With each contraction, blood flow from the mother
to the baby initially ceases as the uterine myometrial
veins are compressed.
• At this point, the mother and baby are physiologically
separated from each other for a few seconds.
• As the contraction begins to subside, the uterine
myometrial arteries re-open,
 allowing blood carrying oxygen and nutrients to
flow from the mother to the baby, and the uterine
myometrial veins reopen, allowing blood carrying
fetal waste products to flow from the baby to the
mother.

19. What are Causes of Fetal Heart
Rate Bradycardia?
• Fetal bradycardia is defined as a decrease in the
baseline FHR to less than 100 beats per minute
1. Fetal Hypoxia: Bradycardia is a late sign of fetal
hypoxia (a continual lack of oxygen).
o The heart rate slows in response to a depression
of heart muscle (myocardial) activity caused by this
continued decrease in needed oxygen.
2. Medications: Medications such as narcotics cause
bradycardia by preventing receptor sites in the fetal
heart muscle from accepting epinephrine, which
works to increase heart rate.

20. 3. Epidurals: cause vasodilation, which leads to
an increase in the incidence of maternal
hypotension during labor WHICH causes
bradycardia indirectly due to a reflex
mechanism, a potential complication for
regional anesthesia.
o Anesthetic medications can produce
bradycardia approximately 5 minutes
following the block. The heart rate then
usually returns to normal baseline rate.

21. 4. Synthetic Oxytocin (Pitocin) may produce
bradycardia by causing a hyperstimulation of the
uterine muscle (myometrium), resulting in hypoxia.
5. Maternal Hypotension: Supine hypotension
syndrome caused by pressure of the uterus and its
contents on the inferior vena cava, when you lay on
your back, results in decreased maternal blood
pressure.
6. Prolapsed Umbilical Cord or Prolonged
Compression of Umbilical Cord.
o Either situation may activate the fetal regulatory
mechanism, causing a stimulation of the vagal
center, which is part of the parasympathetic
nervous system. This results in bradycardia.

22. What Are Causes Of Fetal Heart
Rate Tachycardia?
• Tachycardia: Suspicious tachycardia is defined as
being between 150 and 170 whereas a pathological
pattern is above 170.
1. Fetal Hypoxia. Tachycardia may be an early sign of
hypoxia (fetal lack of adequate oxygen).
2. Medications. Medications used to prevent/stop
premature labor such as terbutaline
(sympathomimetic), have a stimulating effect on
the fetal heart, which increases the rate.
3. Prematurity. A premature baby has an immature
nervous system resulting in an increased heart
rate.

23. 4. Maternal Anxiety. During periods of maternal stress
and anxiety, epinephrine is released into the mother’s
blood stream that crosses the placenta, resulting in an
increase in fetal heart rate.
5. Maternal Fever. Both the mother’s and the baby’s
metabolism is increased, which results in an increased
heart rate
6. Fetal Infection. This may be an early sign of an
intrauterine infection (a stress reaction to
sepsis). Prolonged ruptured membranes may lead to
maternal and fetal infection.
7. Fetal Movement/Stimulation. Benign cause of fetal
tachycardia.

24. 3) Baseline FHR Variability
• Fetal heart rate variability has become one of
the most important indicators in the clinical
assessment of fetal well-being.
• Variability is indicative of a mature fetal neurologic
system

25. What Is Fetal Heart Rate
Variability?
• Fetal heart rate variability is the normal
irregular changes and fluctuations in the fetal
heart rate that shows as an irregular heart rate
seen on the tracing instead of a smooth line.
• The baseline rate variability should vary by at
least 10-15 beats over a period of one minute.
• A decrease in variability can be noted during
fetal sleep.

28. • Variability can be divided into the following
categories:
o Decreased: minimal variability (0-5 bpm).
o Moderate: normal variability (6-25 bpm).
o Marked: saltatory variability (>25bpm).
• A normal, healthy fetal heart rate should possess
average or moderate variability.

29. Decreased Variability May Occur in
The Following Situations:
1. Hypoxia and acidosis: The lack of oxygen and the build-up of
acid in the fetal body depress the fetal heart and nervous
system.
2. All central nervous system depressant medications,
including narcotics and anesthetic agents, depress the fetal
nervous system. Usually, variability increases as the drug is
eliminated from the baby.
3. Prematurity. The fetal nervous system in a premature baby
cannot effectively control the heart rate.
4. Fetal sleep (as noted above).
• Persistent minimal or absent variability is considered an
ominous pattern, requiring immediate delivery.

30. 4) Accelerations
• The fetal heart rate will normally remain steady
or accelerate during uterine contractions.
• Accelerations are defined as a transient increase
in heart rate of greater than 15 bpm for at least
15 seconds (the 15x15 rule).
• Two accelerations in 20 minutes is considered a
reactive trace.
• Accelerations are a reassuring sign as they show
fetal responsiveness and the integrity of the
mechanisms controlling the heart.

31. 5) Periodic or Episodic
Decelerations
• Periodic refers to decelerations that are
associated with contractions;
• Episodic refers to those not associated with
contractions.
• Deceleration = decrease in baseline FHR.

32. THREE Types of Decelerations:
a) Early Decelerations:
b) Late Deceleration:
c) Variable Deceleration:

33. A - Early Decelerations:
• The early deceleration begins at the onset of
the contraction and ends with the end of the
contraction.
• Early deceleration is caused by vagal stimulation
from head compression.
• Early decelerations are not a sign of fetal
problems .

34. Early Decelerations Occur Most Frequently In
The Following Clinical Situations:
1. During sterile vaginal examinations
2. In second stage of labor during pushing
3. During application of internal FHR electrode
4. With cephalopelvic disproportion
5. After amniotic sac has ruptured
6. With vertex presentations

35. B - Late Deceleration:
• Late decelerations are transitory decreases in
heart rate caused by uteroplacental
insufficiency,
o a compromised blood flow to the baby that
does not deliver the amount of oxygen
needed to withstand the stress of labor.
• The late deceleration begins after the onset of
the peak or middle of the contraction and
ends after the contraction.

36. Note:
Persistent late decelerations are
threatening, especially if the
decelerations are associated with
loss of variability.

37. C - Variable Deceleration:
• Variable decelerations are transitory
decreases in fetal heart rate caused
by umbilical cord compression.

38. • A variable deceleration is unrelated to
contractions.
• They may appear V-shaped or U-shaped.
• If a woman could be monitored throughout the
9 months of her pregnancy, it would be
apparent that variable decelerations occur
transiently as the baby grabs the umbilical cord
or the cord gets compressed between the baby
and the uterine wall during fetal movement.

39. • Variable decelerations are not associated with
poor fetal outcome.
• They indicate possible compromise if they
become prolonged or are persistent.

40. Normal/Reactive FHR Pattern
1. Baseline rate 110-160 bpm
2. Moderate variability (>5 bpm)
3. Absence of late, or variable decelerations
4. Early decelerations and accelerations may or
may not be present.

41. Warning Patterns Suggest
Decreasing Fetal Capacity To Cope
With The Stress Of Labor:
1. Decrease in baseline variability (<5bpm)
2. Progressive tachycardia (>160bpm)
3. Decrease in baseline FHR
4. Intermittent late decelerations with good
variability.

42. Ominous Patterns Suggest Possible Fetal
Compromise:
1. Persistent late decelerations, especially with
decreasing variability.
2. Variable decelerations with loss of variability.
3. tachycardia, or late return to baseline
4. Absence of variability
5. Severe bradycardia

43. • If an ominous pattern appears to be
present:
 Intrauterine Resuscitation
a) Has the mother lie on her left side
(remember, lying on her back invites hypotension
which affects baby’s oxygen supply) or in a knee
chest position.
 To alleviate possible cord compression.
b) Reduce or stop any oxytocin she may be
receiving.
c) Initiate tocolytics - to decrease uterine activity
and increase placental blood flow.

44. d) Increase IV fluid - to increase maternal blood flow
volume
e) Give her oxygen by mask - to promote
oxygenation across the placenta
f) Apply an internal monitor - to verify the
accuracy of external monitor readings.
g) Administer amnioinfusion - to decrease pressure
on cord.
• If the heart rate is not restored to normal within 30
minutes, prompt delivery is needed.
• Cesarean section may then become necessary.

45. Effect on Management:
• It has been shown that use of CTG reduces
the rate of seizures in the newborn,
• But there is no clear benefit in the prevention
of cerebral palsy, perinatal death and other
complications of labor.

46. • High negative predictive value :
 >98% of fetuses with a normal CTG will be OK.
• Poor positive predictive value :
 50% of fetuses with an abnormal CTG will be
hypoxic
 but 50% will be OK.
• A normal CTG is a good sign but a poor CTG does
not always suggest fetal distress.