Cardiotocography: CTG antepartum and intrapartum

1. CTG
Aboubakr Elnashar
Benha University Hospital, EgyptAboubakr Elnashar

2. Antepartum
CTG
Aboubakr Elnashar

3. Fetal heart rate recording
1.CTG
2.NST
3.Contraction stress test
4.Nipple stimulation test
5.Acoustic stimulation test
6.Computerized CTG
Aboubakr Elnashar

4. 1. The Non-Stress Test (NST)
(Hammacher et al, 1960)
Idea:
• FHR accelerations:
linked closely with fetal movements
{increased sympathetic output}.
• The long term variability:
{balance between sympathetic & parasympathetic
tone}
• The short term variability (baseline or bandwidth
variability)
{parasympathetic tone}.
Aboubakr Elnashar

5. Steps:
1. left lateral recumbent position.
2. Place and adjust the external tocodynamometer
and ultrasound transducer to obtain the best
possible tracing.
3. Instruct the patient to record fetal movements on
the monitor tracing using the event marker.
4. Observe the EFM tracing until the criteria for a
reactive test are met
(minimum of 20 mins and maximum of 60 mins).
Aboubakr Elnashar

6.  In the event of lack of fetal movement, apply
stimulation e.g. fetal acoustic stimulator.
 Record any relevant clinical information on the
EFM tracing e.g.
blood pressure, temperature, maternal heart rate,
loss of contact
changes in maternal position.
Aboubakr Elnashar

7. Interpretation:
Reactive:
2 accelerations of FHR in 20 min.
Each acceleration 15 beat & lasts 15 secs.
Non-reactive:
no accelerations in 40 min.
Aboubakr Elnashar

8. •Reactive:
increase of FHR to >15 beats/min for > 15 sec
following fetal movements
Aboubakr Elnashar

9. •Nonreactive nonstress test followed by contraction
stress test showing mild late decelerations.
•CS was performed and the severely acidemic fetus
could not be resuscitated.
Aboubakr Elnashar

10.  Positive CST= late deceleration in 50% of UC.
 Non reactive NST= No HR acceleration
 Cessation of fetal movement
 Basal line tachycardia > 160 bpm
 Basal line bradycardia <110 bpm
Sequence of events with placental insufficiency
or hypoxia
Aboubakr Elnashar

11. 2. Fetal heart rate tracings (CTG)
1.Normal/Reassuring
 Baseline
HR: 110-150 b/m
Variability: 10-25 b/m
 At least 2 accelerations
(>15 beats for> 15 seconds in 20 min)
No decelerations.
Aboubakr Elnashar

12. 2. Suspicious/Equivocal Trace.
 Baseline
HR: 150-170 b/m or 100-110 b/m
Variability: Reduced (5-10 b/m for >40 m)
 Absence of accelerations for >40 m
Sporadic deceleration of any type.
Aboubakr Elnashar

13. 3. Abnormal/Pathological
 Baseline
HR: <100 b/m or > 170 b/m
Variability:
No area of normal baseline variability
Silent Pattern (<5 b/m) for >40 min
Sinusoidal pattern (oscillation frequency= 2-5
cycles/min, amplitude of 5-15 b/m) for >40 m
 No accelerations
Repeated late, prolonged (> 1 minute) and
severe variable (>40 b/m) decelerations.
Aboubakr Elnashar

14. A:
Absence of
accelerations,
diminished
variability,
late decelerations
with weak
spontaneous
contractions.
B:
Normal
accelerations
Normal variability
15 beat
Aboubakr Elnashar

15. CTG: Tachycardia
Sinusoidal pattern
Late deceleration Aboubakr Elnashar

16. Intrapartum
CTG
Aboubakr Elnashar

17. Basal Heart Rate Activity
• Rate:
Normal:110-160 increment 5 bpm (10 m segment)
Bradycardia: < 110 bpm
Tachycardia: > 160bpm
• Variability
:Short term= instantaneous (beat to beat v.)
:Long term= oscillatory changes in 1 m
• Sinusoidal:
:Mild is due to sedation
:Marked is due to fetal anemia
 Arrhythmia: Abrupt spiking, bradycardia or tachy
Periodic heart rate Activity
• Acceleration
• Deceleration Aboubakr Elnashar

18. Baseline
The mean FHR rounded to increments of 5 bpm
during a 10-min segment, excluding:
— Periodic or episodic changes
— Periods of marked FHR variability
— Segments of baseline that differ > 25 bpm
Tachycardia
Baseline FHR > 160 bpm
Bradycardia
Baseline FHR < 110 bpm
Aboubakr Elnashar

19. •Fetal
bradycardia
measured
with a scalp
electrode in a
pregnancy
complicated
by placental
abruption
and
subsequent
fetal death.
Aboubakr Elnashar

20. Placental abruption.
In the upper panel, the fetal scalp electrode first detected the
heart rate of the dying fetus. After fetal death, the maternal
electrocardiogram complex is detected and recorded.
The second panel displays an absence of uterine
contractions. Aboubakr Elnashar

21. Variability
Reduced variability is the single most reliable sign of
fetal compromise
The baseline must be for a minimum of 2 min in
any 10-min segment
Fluctuations in the FHR of two cycles per min or
greater
Aboubakr Elnashar

22. Variability is visually quantified as the amplitude of
peak-to-trough in bpm
Absent: amplitude range undetectable
Minimal: amplitude range detectable but 5 bpm
Moderate (normal): amplitude range 6–25 bpm
Marked: amplitude range > 25 bpm
Aboubakr Elnashar

23. Short-term beat-to-beat variability
measured by a fetal scalp electrode
(t= time interval between successive fetal R
waves). Aboubakr Elnashar

24. long-term beat-to-beat variability
ranging between 125 and 135 bpm).
Aboubakr Elnashar

25. (1) Undetectable or absent
(2) Minimal variability:0 -5 bpm
Aboubakr Elnashar

26. 4) Marked variability : >25 bpm
(3)Moderate variability : >5-<25 bpm
Aboubakr Elnashar

27. External fetal heart
recording:
A. lack of long-term
variability at 31 w
during maternal
diabetic ketoacidosis
(pH 6.09).
B. Recovery of fetal
long- term variability
after correction of
maternal acidemia.
Aboubakr Elnashar

28. Sinusoidal Heart Rate
• Flat short term variability
• Ampllitude: 5-15bpm
• 2- 5 cycle/m
• Absence of accelerations
Mild: due to sedation
Marked: due to fetal anemia
Aboubakr Elnashar

29. •Sinusoidal fetal heart rate pattern associated with maternal
intravenous meperidine administration.
•Sine waves are occurring at arate of 6 cycles/min.
Aboubakr Elnashar

30. •Arrhythmia:
•Abrupt spiking
Internal fetal monitoring:
•occasional abrupt beat-
to-beat fetal heart rate
spiking due to erratic
exrasystoles shown in
the superimposed fetal
electrocardiogram.
•The normal infant was
delivered
spontaneously and had
a normal cardiac rhythm
in the nursery.
Aboubakr Elnashar

31. Periodic heart rate Activity
Acceleration
Deceleration
Aboubakr Elnashar

32. Acceleration
A visually apparent increase (onset to peak in less
than 30 sec) in the FHR from the most recently
calculated baseline
The duration= time from the initial change in FHR
from the baseline to the return of the FHR to the
baseline
Aboubakr Elnashar

33. At 32 w and beyond
an acceleration has an acme of 15 bpm above
baseline, with a duration of 15 sec but < 2 min
Before 32 w
an acceleration has an acme 10 bpm above
baseline, with a duration of 10 sec but < 2 min
Prolonged acceleration lasts 2 min, but < 10 min
If an acceleration lasts 10 min, it is baseline
change
Aboubakr Elnashar

34. Deceleration
1. Early deceleration
In association with a uterine contraction, a
visually apparent, usually symmetrical, gradual—
onset to nadir 30 sec—decrease in FHR with
return to baseline
Nadir of the deceleration occurs at the same
time as the peak of the contraction
Aboubakr Elnashar

35. Early
deceleration:
Gradual decrease
in the heart rate with
both onset and
recovery coincident
with the onset and
recovery of the
contraction.
Nadir of the
deceleration is
30seconds or more
after the onset of the
deceleration.
Aboubakr Elnashar

36. 2. Late deceleration
In association with a uterine contraction, a visually
apparent, gradual—onset to nadir 30 sec decrease
in FHR with return to baseline
Onset, nadir, and recovery of the deceleration
occur after the beginning, peak, and end of the
contraction, respectively
Aboubakr Elnashar

37. •Late deceleration.
Gradual decrease in the heart rate
Nadir and recovery occurring after the end of the contraction.
Nadir of deceleration occurs 30 seconds or more after the onset of the
deceleration.
Aboubakr Elnashar

38. •Late
decelerations
{uteroplacental
insufficiency
resulting from
placental
abruption}.
ImmediateCS
•Umbilical artery
pH was 7.05 and
the Po2 was 11
mm Hg.
Aboubakr Elnashar

39. 3. Variable deceleration
An abrupt onset to nadir < 30 sec, visually
apparent decrease in the FHR below the baseline
The decrease in FHR is 15 bpm, with a duration of
15 sec but < 2 min
Complicated variable decelerations
depth >60 bpm for >60 seconds
changes in shape: over-shoot, decreased or
increased baseline FHR following the
decelerations,or
absence of baseline variability in or between
decelerations,
slow recovery
Aboubakr Elnashar

40. Variable decelerations.
abrupt decrease in the
heart rate with onset
commonly varying with
successive contractions.
decelerations measure ≥
15 bpm for 15 seconds or
longer
Onset to nadir phase of
less than 30 seconds.
Total duration is less
than 2 minutes.
Aboubakr Elnashar

41. •Variable
decelerations
B “shoulders” of
acceleration
compared with
deceleration A.
Aboubakr Elnashar

42. FHR effects of partial
occlusion and
complete occlusion of
the umbilical cord
Aboubakr Elnashar

43. 4. Prolonged deceleration
Visually apparent decrease in the FHR below the
baseline
Deceleration is 15 bpm, lasting 2 min but < 10 min
from onset to return to baseline
Aboubakr Elnashar

44. Abrupt decrease
>15 bpm
Often drops<100
>2 m & < 10 m
Variable pattern
•Prolonged
deceleration
{uterine hyperactivity}
Approximately 3
minutes are shown but
FHR returned to
normal after uterine
hypertonus resolved.
Vaginal delivery later
ensued.
Aboubakr Elnashar

45. Fetal heart rate
effects of
manual
compression of
a prolapsed
umbilical cord in
a 25-week
footling breech.
A shows the
effects of 25-
second
compression
compared with
40 seconds in
B.
Aboubakr Elnashar

46. Early Deceleration
Late Deceleration
Variable Deceleration
Abrupt decrease
 >15 bpm
Often drops<100
>15 S& < 2 m
Variable pattern
Abrupt decrease
 >15 bpm
Often drops<100
>2 m & < 10 m
Variable pattern
Prolonged Deceleration
may drops<100
Usually did not drops<100
Decelerations
Aboubakr Elnashar

47. Indications for continuous EFM
1. High-risk pregnancies where there is an
increased risk of perinatal death, cerebral palsy or
neonatal encephalopathy.•B
2. Where oxytocin is being used for induction or
augmentation of labour.•C
Aboubakr Elnashar

48. INTERPRETATION
Aboubakr Elnashar

49. a)Normal/Reassuring Trace
- At least two accelerations (> 15 beats per minute
for >15 seconds) in 20 minutes
- Baseline heart rate: 110-150 bpm
- Baseline variability: 5-25 bpm
- Early decelerations (in late first stage of labour)
Aboubakr Elnashar

50. b)Suspicious/Equivocal Trace
- Absence of accelerations for >40 minutes
(non reactive)
- Baseline heart rate: 150-170 bpm or 100-110 bpm
(normal variability, no decelerations)
- Silent pattern (<5 bpm for >40 minutes) although
normal baseline (110-150 bpm), no
decelerations
- Baseline variability >25 bpm in the absence of
accelerations
- Variable decelerations (depth <60 bpm, duration
<60 seconds)
- Occasional transient prolonged bradycardia if
FHR drops to <80 bpm for >2 minutes or
<100 bpm For >3 minutes
Aboubakr Elnashar

51. b)Abnormal/Pathological Trace
- Baseline FHA> 150 bpm + silent pattern and/or repeated late or
variable decelerations
- Silent pattern for >90 minutes
- Complicated variable decelerations (depth >60 bpm for >60
seconds, changes in shape: over-shoot, decreased or
increased baseline FHR following the decelerations, or absence
of baseline variability in or between decelerations, slow
recovery)
- Combined/biphasic decelerations (variable followed by late)
- Prolonged bradycardia in a suspicious trace
- Prolonged bradycardia> 10 minutes with no signs of recovery
- Repeated late decelerations
- Pronounced loss of baseline variability regardless of baseline
FHR with shallow late decelerations
- Sinusoidal pattern with no accelerations
Aboubakr Elnashar

52. Aboubakr Elnashar

53. MANAGEMENT
a)Normal/Reassuring
risk of fetal hypoxia in spontaneous labour is low.
Manage normally.
b)Suspicious/Equivocal
continue EFM
amniotomy should be performed
+/- fetal scalp blood pH if meconium stained
liquor is present.
Aboubakr Elnashar

54. Initial Evaluation and Treatment of Nonreassuring
Fetal Heart Rate Patterns
Discontinuation of any labor stimulating agent
Cervical examination:
umbilical cord prolapse or
rapid cervical dilation or
descent of the fetal head
Changing maternal position to left or right lateral
recumbent position, reducing compression of the
vena cava and improving uteroplacental blood flow
Aboubakr Elnashar

55. Monitoring maternal blood pressure level for
evidence of hypotension, especially in those with
regional anesthesia—if present, treatment with
ephedrine or phenylephrine may be warranted
Assessment of patient for uterine hyperstimulation
by evaluating uterine contraction frequency and
duration
Aboubakr Elnashar

56. During episodes of abnormal FHR patterns when
the mother is lying supine, the mother should adopt
the left-lateral position.•B
In the presence of abnormal FHR patterns and
uterine hypercontractility not secondary to oxytocin
infusion, tocolysis should be considered. A
suggested regime is subcutaneous terbutaline
0.25 milligrams.•A
Aboubakr Elnashar

57. c)Abnormal/Pathological
Amniotomy
Fetal scalp blood pH if meconium stained liquor
to determine subsequent management or
Deliver if clinically indicated.
Deliver if fetal scalp pH required but not
obtainable i.e. if cervix not sufficiently dilated or
equipment not available.
Aboubakr Elnashar

58. In cases of suspected or confirmed acute fetal
compromise, delivery should be accomplished as
soon as possible, accounting for the severity of the
FHR abnormality and relevant maternal factors.
The accepted standard has been that ideally this
should be accomplished within 30 minutes. •B
Aboubakr Elnashar

59. Fetal blood sampling
 should be undertaken with the mother in the left-lateral
position.•B
Contraindications to fetal blood sampling :•B
Maternal infection (e.g. HIV, hepatitis viruses and
herpes simplex virus)
Fetal bleeding disorders (e.g. haemophilia)
Prematurity (< 34 weeks).
Where there is clear evidence of acute fetal
compromise (e.g. prolonged deceleration greater than
three minutes), fetal blood sampling should not be
undertaken and the baby should be delivered urgently.•.
Aboubakr Elnashar

60. All scalp pH estimations should be interpreted taking into account
the previous pH measurement,
the rate of progress in labour and the
clinical features of the mother and baby.
Aboubakr Elnashar

61. Maternal facial oxygen therapy
Prolonged use of maternal facial oxygen therapy
may be harmful to the fetus and should be
avoided.
There is no research evidence evaluating the
benefits or risks associated with the short-term use
of maternal facial oxygen therapy in cases of
suspected fetal compromise .•C
Aboubakr Elnashar

62. Thank you
Aboubakr Elnashar