The use of cardiotocogragh in obstetric practice is a sure way for early identification of fetal compromise. Thus there is need for regular and structured training of labour ward staff to ensure proper use of this technology, thereby decreasing perinatal mobidity and mortality.

1. ELECTRONIC FETAL MONITORING _CARDIOTOCOGRAPH
IN THE MANAGEMENT OF LABOUR
PRESENTED BY
DR COURAGE J. ILUMA
NDUTH OKOLOBIRI

2. OUTLINE
• INTRODUCTION
• INDICATIONS
• COMPONENT OF THE CTG MACHINE
• MATERNAL POSITION FOR CTG ACQUISITION
• ANALYSIS OF TRACINGS
• DESCRIPTION OF CTG TRACINGS
• MANAGEMENT BASED ON CTG TRACING
• ADVANTAGES
• DISADVANTAGES
• CONCLUSION

3. INTRODUCTION
• Cardiotocograph is a technical continuous non invasive
monitor of foetal heart rate and uterine contraction during
pregnancy.
• Foetal cardiac behaviour is regulated through the autonomic
nervous system and by vasomotors, chemoreptors and
baroreceptors.

4. INTRODUCTION
• Pathological events, such as foetal hypoxia
modify these signals and hence cardiac
response, including foetal heart rate patterns,
can be detected and recorded in the CTG.
• It is used both in antepartum and
intrapartum to monitor and assess fetal well
being.

5. INTRODUCTION
• Cardiotocograph remains one of the cornerstones of
making diagnosis in foetal distress. The monitoring of foetal
heart rate in labour aims to identify hypoxia before it is
sufficient to lead to long term poor neurological
outcome(cerebral palsy) and mortality.

6. INTRODUCTION CONT.
• Continuous electronic fetal monitoring was
introduced into obstetrics practice during the late
1960s.
• Invented by Orvan Hess, Edward Hon and
developed by Hammacher.
• When first introduced EFM was used primarily in
complicated pregnancies but gradually it is being
used in most pregnancies.
• By 1978 it was estimated that nearly two-third of
American women were being monitored
electronically in labour.

7. • In 2002 approximately 3-4 million American women,
comprising 85% of all live births underwent electronic fetal
monitoring( EFM).
• In Nigeria, it is not used generally except in most tetiary
hospitals.

8. COMPONENTS OF CTG
MACHINE
• MONITOR
• TWO TRANSDUCERS:
1. ULTRASOUND TRANSDUCER THAT MEASURES FHR.
2. PRESSURE SENSITIVE TRANSDUCER(TOCODYNAMOMETER)

9. THE CTG

10. INDICATIONS FOR CTG
MONITORING IN LABOUR
• Previous C/S
• Hypertensive disorders in pregnancy
• Antepartum haemorrhage
• IUGR
• twin pregnancy
• Breech presentation
• Preterm labour
• Meconium stained liquor
• DM in pregnancy
• Sickle cell disease in pregnancy
• Thyroid disease in pregnancy

11. INDICATIONS CONTD
• Abnormal FHR detected by intermittent
auscultation
• Maternal pyrexia
• Fresh bleeding developing in labour
• Oxytocin use for induction and augmentation of
labour
• Pregnancy following IVF.
• Elderly primigravida.
• Patient request etc

12. MATERNAL POSITION FOR
CTG ACQUISITION
• Preferred maternal position for CTG
acquisition :
•Lateral recumbent position
•Half sitting position
•Upright position
The CTG machine is connected to the pregnant
woman’s abdomen using two transducers.
1. The ultrasound transducer for FHR
measurement
2. The TOCODYNAMOMETER for uterine
contractions.

13. PRINCIPLES OF
MONITORING
 Works via ultrasound.
 Signals are sent via uss transducers, graphically interpreted.

15. STORAGE OF TRACINGS
• All CTG tracings need to be identified with patient’s name,
place of recording, paper print out, date and time when
acquisition started and ended and indication.
• This CTG tracings should be stored securely with the
woman’s medical records for at least 25years.

16. ANALYSIS OF TRACINGS
B Ra V A D O
• 1. Baseline heart rate
• 2. Variability
• 3. Acceleration
• 4.Deceleration
• 5 Overall impression
- Reassuring
- Non reassuring
- omnious

17. BASELINE FHR
• This is the mean level of most horizontal and
less oscillatory FHR Segment. It is estimated
in a time period of 10mins.
• Normal baseline FHR_ 110-160bpm
• Greater than 160pm_ fetal tachycardia
• Less than 110bpm_ fetal bradycardia

19. FETAL TACHYCARDIA
• FHR greater than 160bpm.
• 161-180bpm _mild
• 181-200bpm _ severe
• Greater than 200bpm _ severe, omnious

20. CAUSES OF TACHYCARDIA
• Maternal fever
• Fetal infection
• Maternal dehydration and anxiety
• Maternal thyrotoxicosis
• Fetal anaemia
• Fetal tachyarrhythmias
• Drugs like sympathomimetics and
parasympatholytics

22. FETAL BRADYCARDIA
• 100-109bpm _mild
• 80- 99bpm _severe
• Less than 80bpm _severe, omnious sign

23. CAUSES OF BRADYCARDIA
• Post date pregnancy
• Maternal hypothermia
• Congenital heart block
• Uterine hypertonicity
• Maternal medications like sedative opiates
and beta blockers
• Prolong cord compression
• Vigorous vaginal examination

25. BASELINE VARIABILITY
• It is the fluctuation of FHR resulting from influence of
autonomic nervous system.
• It is evaluated as the average bandwidth in 1minute
segment.
• NORMAL VARIABILITY: 5- 25bpm
• REDUCED VARIABILITY: less than 5bpm for more than
30minutes in baseline segment or for 3 minutes during
deceleration.

26. BASELINE VARIABILITY
REDUCED BASELINE VARIABILITY
• Central nervous system hypoxia
• Fetal acidosis
• Resulting decreased sympathetic and parasympathetic
activity.
• Previous cerebral injury,
• Infection
• Administration of CNS depressant or parasympathetic
blockers.
• Fetal sleep
• Prematurity

27. BASELINE VARIABILITY
INCREASED BASELINE VARIABILITY
• > 25bpm lasting more than 30mins.
• The pathophysiology of this pattern is incompletely
understood.
• May be linked with recurrent decelerations.
• When hypoxia/acidosis evolves very rapidly.
• Presumed to be caused by fetal autonomic
instability/ hyperactive autonomic system.

30. ACCELERATION
• It is an increase in FHR over baseline of at least
15bpm for at least 15 seconds but less than
10minutes.
• Most acceleration coincides with foetal movement
and are a sign of neurologically responsive foetus
that does not have hypoxia/acidosis.
• Reassuring.

32. DECELERATION
• It is decrease in FHR below the baseline of at
least 15bpm for at least 15seconds.
• Deceleration could be:
• EARLY
• LATE
• VARIABLE
• PROLONGED

33. EARLY DECELERATION
• Early deceleration are uniform .
• Repetitive in association with uterine
contractions .
• The nadir of deceleration coincides with
the peak of uterine contraction.
• Due to foetal head compression at the
later stage of labour .
• Does not indicate foetal hypoxia/ acidosis.

35. LATE DECELERATION
• Also uniform and repetitive in relation to uterine
contractions .
• Delayed in timing with nadir late in relation to
peak uterine contractions (ocurring 20secs after the
peak of contraction) .
• Recovers after the end of contraction.
• Late deceleration is almost always indicative of
uteroplacental insufficiency and decreased
intervillous exchange between the mother and
fetus resulting in fetal hypoxia.

37. Late deceleration is associated with;
1. IUGR,
2. oligohydramnios,
3. placenta abruption,
4. Excessive uterine activity,
5. Maternal hypotension,
6. Anaemia
7. ketoacidosis

38. VARIABLE DECELERATION
• Deceleration that exhibit a rapid drop (onset
to nadir in less than 30seconds)
• Good variability within deceleration.
• Rapid recovery to baseline.
• Varying size, shape and relationship to
uterine contractions.
• It constitute the majority of deceleration in
labour.
• It is seen in cord compression.

40. PROLONGED DECELERATION
• Deceleration lasting more than 3 minutes.
• These are likely to include chemoreceptor mediated
component and thus indicate hypoxaemia.
• Prolonged deceleration causes include:
-Uterine hyperactivity.
-Cord entanglement,
-Maternal supine position.
-Others include: epidural, spinal and para cervical
analgesia.

42. CONTRACTIONS
They are ball shaped gradual increase in the uterine signals
followed by a roughly symmetrical decrease.
TACHYSYSTOLE: excessive frequency of contractions in the
excess of 5 contractions in 10minutes.

43. PRINCIPLES FOR
INTRAPARTUM CTG TRACE
INTERPRETATION
When reviewing the CTG trace, assess
and document contractions and all 4
features of FHR. If there is a stable
baseline FHR between 110- 160bpm
and normal variability, continue usual
care as the risk of foetal acidosis is
limited.

44. DESCRIPTION OF CTG
TRACE
DESCRIPTION BASELINE
FHR(BPM)
BASELINE
VARIABILITY(BP
M)
DECELERATION
REASSURING 110 - 160 5 - 25 None or early
Variable
deceleration with
no concerning
characteristics for
less than 90
minutes.

45. DESCRIPTION OF CTG TRACE
DESCRIPTIO
N
BASELINE
FHR(BPM)
BASELINE
VARIABILIT
Y (BPM)
DECELERATION
NON
REASSURING
100 – 109
OR 161 -
180
<5 for 30 –
50 minutes
OR > 25 for
15 – 25
minutes
Variable deceleration with no
concerning characteristics for 90
minutes or more OR
Variable deceleration with any
concerning characteristics in up to
50% of contraction for 30 minutes or
more OR
Variable deceleration with any
concerning characteristics in over 50%
of contractions for < 30mins OR
Late deceleration in over 50% of
contractions for < 30mins with no
maternal or fetal clinical risk factor
such as vaginal bleeding or significant
meconium.

46. DESCRIPTION OF CTG TRACE
DESCRIPTION BASELINE
FHR(BPM)
BASELINE
VARIABILI
TY(BPM)
DECELERATION
ABNORMAL < 100 OR
>180
< 5 for
more than
50mins or
>25 for
more than
25mins
Variable deceleration with any
concerning characteristics in over
50% of contractions for 30minutes
(or less if any maternal or foetal
clinical risk factors)OR
late deceleration for 30mins(or
less if any maternal or foetal
clinical risk factors)OR
Acute bradycardia OR
Prolonged deceleration lasting
3mins or more.

47. Concerning characteristics for variable
deceleration are:
• Variable deceleration lasting> 60secs
• Reduced baseline variability within
deceleration
• Failure to return to baseline
• Biphasic shape
• No shouldering

48. MANAGEMENT BASED ON
INTERPRETATION OF CTG TRACING
CATEGORY DEFINITION MANAGEMENT
NORMAL All features are
reassuring
• Continue CTG and usual care
• Talk to the woman and her birth
companion about what is happening
SUSPICIOUS 1 non reassuring
feature and 2
reassuring features
• Correct any underlying causes or
uterine hyper stimulation
• Perform a full set maternal observation
• Start one or more conservative
measures
• Inform an obstetrician or a senior
midwife
• Document a plan for reviewing the
whole clinical picture and the CTG
findings
• Talk to the woman and her birth
companion about what is happening
and take her preferences into account

49. MANAGEMENT BASED ON
INTERPRETATION OF CARDIOTOCOGRAPH
TRACES
CATEGORY DEFINITION MANAGEMENT
PATHOLOGIC
AL
1 abnormal OR
2 non reassuring
features
• Obtain a review by an obstetrician or
senior midwife
• Exclude acute events( e,g cord prolapse,
suspected placental abruption or
suspected uterine rupture)
• Correct any underlying causes such as
hypotension or uterine hyperstimulation
• Start 1 or more conservative measures
• Talk to the woman and her birth
companion about what is happening and
take her preference into account.
• If the CTG trace is still pathological after
implementing conservatives measures:
• Obtain a further review by obstetrician or
senior midwife
• Offer digital fetal scalp stimulation and
document the outcome.

50. • If the CTG trace is still
pathological after fetal
scalp stimulation:
• Consider fetal blood
sampling
• Consider expediting
the birth
• Take the woman`s
preferences into
account.

51. NEEDS FOR
URGENT
INTERVENTI
ON
Acute bradycardia, or a
single prolonged
deceleration for 3mins
or more
• Urgently seek obstetric help
• If there has been an acute event
(e.g cord prolapse, suspected
placental abruption or suspected
uterine rupture), expedite the birth
• Correct any underlying causes
such as hypotension or uterine
hyperstimulation
• Start 1 or more conservatives
• Make preparation for an urgent
birth
• Talk to the woman and her birth
companion about what is
happening and take her
preference into account
• Expedite the birth if the acute
bradycardia persists for nine
minutes
• If the FHR recovers at any time up
to 9 mins, assess any decision to
expedite the birth, in discussion
with the woman.

52. ADVANTAGES
OF CTG IN LABOUR
• Early identification of fetal compromise.
• Reduces the stress of continuous manual monitoring.
• Decreases the rate of birth injury due to hypoxia.

53. • Its use is associated with high caeserean section rate and
instrumental vaginal delivery .
• Cost of equipment.
• It requires training to use equipment and analyse results.
• One on one use of device.
DISADVANTAGES/
DRAWBACKS OF CTG IN
LABOUR

54. SINUSOIDAL PATTERN
• A regular, smooth, undulating signal, resembling a
sine wave.
• Amplitude of 5 – 15bpm and a frequency of 3 – 5
cycles per minute.
• Last > 30mins.
• Pathological basis is incompletely understood, but
it occurs in association with-
• severe anaemia, as is found in anti-D
alloimunization, fetal-maternal haemorrhage, twin-
twin transfusion syndrome and ruptured vasa
previa.

55. PSEUDOSINUSOIDAL
PATTERN
• A pattern resembling the sinusoidal pattern.
• more jagged “saw- tooth” appearance.
• Its duration seldom exceeds 30minutes and it is
characterized by normal pattern before and after.
• It is described after analgesic administration to the
mother, and during periods of sucking and other
mouth movement.

56. CONCLUSION
• The use of cardiotocogragh in obstetric
practice is a sure way for early identification
of fetal compromise. Thus there is need for
regular and structured training of labour
ward staff to ensure proper use of this
technology, thereby decreasing perinatal
mobidity and mortality.

57. •THANKS

58. REFERENCES
• OBSTETRICS BY TEN TEACHERS 18th Edition.
• COMPREHENSIVE OBSTETRICS IN THE TROPICS .
• Dewhurst's Textbook of Obstetrics and Gynaecology 9th
Edition.
• U_ tube Slide share, Electronic Fetal Monitoring made
easy.
• Electronic Fetal Monitoring. Update course FMOG, 2021.
• NICE GUIDELINE( FEBRUARY 2017)
• FIGO CONSENSUS GUIDELINE ON INTRAPARTUM FETAL
MONITORING: CARDIOTOCOGRAPHY.

59. QUESTIONS
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