Undergraduate course lectures in PB&GYNE prepared by Dr Manal Behery ,Professor of OB&GYNE .Faculty of medicine ,Zagazig University

1. INTRAPARTUM FETAL MONITORING
Dr Manal Behery
Professor OB&GYNE
2014

2. Methods available for fetal monitering
in labor
 Intermittent auscultation
CTG Fetal electrocardiography
Scalp stimulation
 Vibroacoustic stimulation
Fetal scalp sampling  PH determination
Fetal pulse oximetry

3. Types of Intermittent
Monitors

4. Intermittent Auscultation

5. The three unique risk factors for fetus
during labor
Factor of uterine contraction
Factor of cord accident
Factor of head compression

6. Factor of uterine contraction
Oxy –Hb 0.19 micromol/100Gm of brain
Cerebral O2 saturation 9%
•
 In spite of this slightly worrying picture, Nothing
harmful effect happen if
fetus is healthy
labor contraction are normal
Placenta has adequate reserve

7. Factor of head compression
Some degree of compression is inevitable during normal labor
But
Excessive compression over long period causing
supermoulding as in obstructed labor may cause fetal hypoxia

8. Factor of cord accident
Only during labor cord prolapse ,presentation and
entanglements become apparent either by compression or
stretch secondary to uterine contraction

9. Aim of intrapertum fetal monitering
 1- to detect the earliest stages of hypoxia so therapy
can be directed to prevent asphyxia and asphyxial
damage( e.g Cerebral palsy)
 2-To Improve perinatal morbidity & mortality

10. What is Cardiotocography(CTG)?
It is a paper record of the continuous FHR blotted
simultaneously with a record of uterine activity
Ultrasound (cardio) transducer
Tocotransducer

11. CTG reCords
Non stress test
without uterine contraction
Stress test
in correlation to uterine contraction

12. External monitoring

13. Internal monitoring

14. Intrapartum Fetal monitoring CTG

15. FHR trace(4 components)
 Base line FHR
 Baseline variability
 Accelerations
 Decelerations

16. Baseline FHR
The dominant reading taken ≥10 min
Normal baseline FHR 110-160(pbm)
Controlled by atrial pacemaker

17. Baseline FHR

18. Tachycardia FHR>160 bpm

19. Baseline bradycardia FHR<110bpm

20. Baseline varibility
 The Oscaltatory pattern of FHR when recorded on a graph.
 Short term(beat t0 beat)
 is the fluctuation of HR over short interval
 Long term
is the fluctuation over long interval(≥2 min)
 Indicates mature fetal neurologic system

21. Baseline varibility
Short term variability
(scalp electrode)
Long term variability
defined as 3-5 cycle/min

22. Baseline varibility

23. No variability (0-2 ครั้ง/นาที)
Mark variability (>25 ครั้ง/นาที)
Moderate variability (11-25
ครั้ง/นาที)
No variability (0-2 ครั้ง/นาที)
Moderate variability (11-25
ครั้ง/นาที)
Minimal variability (3-4 ครั้ง/นาที)

24. Accelaration
Increase in FHR with contraction or with other activities
Increase15pbm
lasting 15 sec
Return to base line <2 min

25. Accelaration

26. Decelerations
Decelerations
 Transient slowing of FHR below
The baseline level> 15 bpm
 and lasting for 15 sec.
or more.

27. Early Decelerations
 Uniform
 Synchronous with contraction (mirror image)
 Rarely fall below 110 (pbm)
 Due to head compression
 Should not be disregarded
if they appear early in labor or Antenatal.

28. Early Decelerations

29. Late Deceleration
Uniform
Start after peak of contraction
Associated with decreased
Variability
Reflect a baroreceptor
response
Indicate fetal hypoxia

30. Late Deceleration

31. Repetitive late decelration
increases risk of
Umbilical artery acidosis
Apgar score < 7 at 5 ms
Cerebral palsy
If associated with
decrease or loss of
variability

32. Variable Deceleration (the most
common type)
Varible in appearance and Timing.
May be assoicated with increased variability .
Reflect umbilical cord compression
• Of no clinical significance if non recurrent
.

33. Variable Deceleration

34. Tyes of decleration

35. Prolonged Deceleration
deceleration
 A deceleration that lasts more than 90
 seconds (but less than 10 minutes)
 Drop in FHR of 30 bpm or More
 Reduction in O2 transfer to placenta.
 Associated with poor neonatal outcome

36. Prolonged Deceleration

37. What are the features of a normal
tracing?
Baseline FHR 110-160 BPM
Baseline Variability > 5 pbm (10-25)
2 Accelerations > 15 BPM > 15 sec / 20 min trace
No decelrations

38. Normal -Reassuring CTG

39. Interpertation of CTG
Normal -Reassuring(R)- CTG with all 4
Features
Suspicious (equivocal)- one non reassuring
category and reminder are reassuring
Abnormsal -Non reasurring (NR) - 2 or
more non-reassuring categories or one or
more abnormal categories.

40. Interpertation of CTG

41. Consider
Intrapartum / antepartum trace.
Stage of labour
Gestation
Fetal presentation.
Any augmentation
Medications

42. Is Normal CTGs always Reassuring?
 With normal CTC the chance of fetus to develop hypoxia is
1.5% due to unpredictable acute events
 So a normal CTG is always Reassuring

43. Is NR CTGs always worrisome ?
 60% CTG in Labour have 1 abnormal feature
 Only 15-20% of NR CTGs are pathological.
 High false positive rate with unnecessary operative
intervention for fetal distress.
 Thus NR CTG is not always worrisome.

44. ?? To reduce CS….

45. Consider these factors with abnormal
CTG
 Maturity of the fetus
Reduced variability and baseline tachycardia is conmen in
preterm
 State of maternal pulse
Drugs may cause maternal and fetal tachycaedia
 Check blood pressure for hypotension in patients on
epidural.

46. Consider these factors with abnormal
CTG
 Posture of patient during CTG
o Supine position give abnormal tracing
o Some cord compression can get released by change
posture and must be tried with variable deceleration
 Congenital fetal malformation
Color Doppler of fetal heart to exclude congenital heart block

47. Correct reversible causes
Change mother position from supine to left lateral
position-----increase uterine blood flow
Improve maternal oxygenation—100% O2 by masK
Correct maternal hypotension –IV fluid
Decrease or stop any oxytocin infusion
Remove vaginal prostaglandins

48. Secondary tests of fetal well-being
Vibro-acoustic stimulation
Used as a substitute for scalp sampling when CTG –is NR
Normal ----------if FHR acceleration > 15 bpm for 15
seconds within 15 seconds after the stimulation with
prolonged fetal movements.
Abnormal ----Only 50% have acidotic PH

49. Fetal blood sampling
If the pH >7.25 --- observe.
If the pH 7.2 and 7.25---repeated
within 30 minutes.
If the pH <7.2----repeat immediately
If pH still low -- Prompt delivery

50. Scalp stimulation.
Firm digital pressure
Gentile pinch by atramatic Allis forceps
Fetal pulse oximetry.

51. THANK YOU