1. ELECTRONIC FETAL HEART RATE MONITORING: Where are we and where are we going?
Gary D. V. Hankins, M.D.
The University of Texas Medical Branch
Special thanks –
Dr. George Macones and Dr. Cathy Spong

2. A Reevaluation Workshop April 28-29-2008
ELECTRONIC FETAL HEART RATE MONITORING:
A Reevaluation Workshop
April
Co-sponsored by the Pregnancy and Perinatology Branch (PPB) at the National Institute of Child Health and Human Development,
The American College of Obstetricians and Gynecologists (ACOG)
And
The Society for Maternal Fetal Medicine (SMFM)

3. Represented NICHD – PPB SMFM ACOG ACNM AWHONN AAP RCOG CCOG
National Cardiovascular Center - Japan

4. Breakout Groups Group 1: Systems (two vs three vs five tiers)
Rationale implications
Group 2: Definitions of FHR patterns
Baseline FHR
Baseline FHR variability
Acceleration
Group 3: Definitions of FHR patterns
Late deceleration
Early deceleration
Variable deceleration
Prolonged deceleration

5. Group 1 Leader Gary Hankins Rapporteur Catherine Spong Sean Blackwell
Peter Cherouny
Jeff Ecker
Eric Eichenwald
Bill Grobman
David James
Tekoa King
Victoria Lanni Korker
Harold Pollard
Michael Swan

6. Group 2 Leader Tom Moore Rapporteur Uma Reddy Vince Berghella
Laura Dean
Sean Esplin
Cynthia Gyamfi
Valerie King
Robert Liston
Donald Mcintire
David Miller
Kathleen Rice Simpson
Caroline Signore

7. Group 3 Leader John Hauth Rapporteur Rosemary Higgins Alison Cahill
Eric Carlson
Mary D’Alton
Roger Freeman
Tomoaki Ikeda
Elizabeth Lapeyer
Ken Leveno
Julian Parer
Anne Santa-Donato
Richard Depp

11. ‘The RCOG System – 2001’
‘The use and interpretation of cardiotocography in intrapartum fetal surveillance’
RCOG Evidence-based Clinical Guideline No 8
Adopted by National Institute of Clinical Excellence (NICE)
Published for May 2001
For this Workshop focus on terminology used in EFM
Courtesy of Dr. David James

12. Four arguments for development of EFM Guideline
Intrapartum hypoxia
1% of all labors
10% perinatal deaths - CESDI
(Confidential Enquiry into Stillbirths and Deaths in Infancy)
IP hypoxic death rate = 0.8:1000 births
10% CP cases
IP hypoxic CP rate = 0.1:1000 births
Courtesy of Dr. David James

13. Four arguments for development of EFM Guideline
EFM use
239/248 (96.4%) maternity units in UK use EFM
26% did not have an EFM Guideline (30% in units > 3000 dels)
Fetal blood sampling used in 88%
Courtesy of Dr. David James

14. Four arguments for development of EFM Guideline
Suboptimal EFM use
CESDI (Confidential Enquiry into Stillbirths and Deaths in Infancy) 70% of IP deaths have Grade II/III suboptimal care
Majority of examples relate to EFM
Failure to recognize
Failure to act
Communicate failure
Courtesy of Dr. David James

15. Four arguments for development of EFM Guideline
Medicolegal issues
> $800 million estimate of NHS medicolegal costs currently
> 60% are obstetric cases
Majority of obstetric cases relate to fetal monitoring in labor
Courtesy of Dr. David James

16. Courtesy of Dr. David James

17. Courtesy of Dr. David James

18. SOGC.org

19. Classification of intrapartum EFM tracings Normal tracing
Previously “Reassuring”
Atypical Tracing
Previously “Non-reassuring”
Abnormal Tracing
Baseline
bpm
Bradycardia bpm
Tachycardia > 160 for > 30 min to < 80 min.
Rising baseline
Bradycardia < 100 bpm
Tachycardia > 160 for < 80 min.
Erratic baseline
Variability
6-25 bpm
≤ 5 bpm for < 40 min.
≤ 5 bpm for min.
≤ 5 bpm for > 80 min.
≥ 25 bpm for > 10 min.
Sinusoidal
Decelerations
None or occasional uncomplicated variables or early decelerations
Repetitive (≥ 3) uncomplicated variable decelerations
Occasional late decelerations
Single prolonged deceleration
> 2 min. but < 3 min.
Repetitive (≥ 3) complicated variables:
deceleration to < 70 bpm for > 60 secs.
loss of variability in trough or in baseline
biphasic decelerations
overshoots
slow return to baseline
baseline lower after deceleration
baseline tachycardia or bradycardia
Late decelerations > 50% of contractions
Single prolonged deceleration > 3 min. but < 10 min.
Accelerations
Spontaneous accelerations present
(FHR increases > 15 bpm lasting
> 15 seconds (< 32 weeks’ gestation increase in the FHR > 10 bpm lasting > 10 seconds)
Accelerations present with fetal scalp stimulation
Absence of acceleration with fetal scalp stimulation
Usually absent*
ACTION
EFM may be interrupted for periods up to 30 min. if maternal-fetal condition stable and/or oxytocin infusion rate stable
Further vigilant assessment required, especially when combined features present.
ACTION REQUIRED
Review overall clinical situation, obtain scalp pH if appropriate/prepare for delivery
*Usually absent, but if accelerations are present, this does not change the classification of tracing.

21. Risk of acidemia, evolution of FHR patterns to more serious risk,
and recommended action
Variable
Risk of acidemia
Risk of evolution
Action
Green
Very low
None
Blue
Low
Conservative techniques & begin preparation
Yellow
Moderate
Conservative techniques & increased surveillance
Orange
Borderline/acceptably low
High
Conservative techniques & prepare for urgent delivery
Red
Unacceptably high
Not a consideration
Deliver
Am J Obstet Gynecol 2007; 26.e3

22. Conservative ameliorating techniques for the modification of variant FHR Patterns
Position Change
Hyperoxia
Correct hypotension
Adequate intravascular volume
Correct excessive contractions (eg, decrease oxytocin)
Avoid constant pushing
Tocolysis
Amnioinfusion to correct amniotic fluid deficit
Am J Obstet Gynecol 2007; 26.e3

23. Risk categories for fetal acidemia related to FHR variability, baseline rate and presence of recurrent decelerations.
MODERATE (NORMAL) VARIABILITY No
Early
Mild VD
Mod VD
Sev VD
Mild LD
Mod LD
Sev LD
Mild PD
Mod PD
Sev PD
Tachy B Y O
Normal G
Mild Brd
Mod Brd
Sev Brd
MINIMAL VARIABILITY No
Early
Mild VD
Mod VD
Sev VD
Mild LD
Mod LD
Sev LD
Mild PD
Mod PD
Sev PD
Tachy B Y O R
Normal
Mild Brd
Mod Brd
Sev Brd
ABSENT VARIABILITY No
Early
Mild VD
Mod VD
Sev VD
Mild LD
Mod LD
Sev LD
Mild PD
Mod PD
Sev PD
Tachy R
Normal O
Mild Brd
Mod Brd
Sev Brd
Sinusoidal R
Marked Variability Y
VD, Variable decelerations; LD, Late decelerations; PD, Prolonged decelerations; Brd, Bradycardia; Tachy, Tachycardia
G, Green; B, Blue; Y, Yellow; O, Orange

24. EFM Interpretation Systems
1997 NICHD: 2 tier
RCOG: 3 tier
Extensive vetting and peer review
National implementation, 50% drop in intrapartum death rate
SOGC: 3 tier
Miller: 3 tier
Least stringent
Common sense approach
Definition, interpretation, management
Parer: 5 tier
Applied knowledge, interdisciplinary
Variability driven

25. Outline of Workshop Findings
Assumptions
Describing FHR tracing components
Categories of the new 3 tier system
Meaning and actions required for each tier

26. Assumptions (1)
The definitions were developed for visual interpretation of FHR patterns. Computerized interpretation is not yet mainstream.
Both FHR and uterine activity should be of adequate quality for visual interpretation.

27. Assumptions (2)
Episodic patterns are those not associated with uterine contractions.
Periodic patterns are those associated with uterine contractions
Characterized as either “abrupt” or “gradual” onset
No distinction is made between short term and long term variability

28. Assumptions (3)
FHR tracings should be evaluated in context of clinical conditions including:
gestational age,
medications,
maternal medical conditions, and
fetal conditions (eg, growth restriction, known congenital anomalies, fetal anemia, arrhythmia etc).

29. Assumptions (4): An EFM tracing requires qualitative and quantitative description of:
Uterine contractions
Baseline FH rate
Baseline FHR variability
Presence of accelerations
Periodic or episodic decelerations
Changes or trends of FHR patterns over time

30. Describing Contractions
Number of UCs per 10 minute window
Averaged over 30’
Normal: ≤ 5 contractions in 10’
Tachysystole: > 5 contractions in 10’
Presence or absence of decelerations
Spontaneous and stimulated labor
Hyperstimulation and hypercontractility are to be abandoned.

31. Describing FHR Baseline
Rounded to 5 bpm
Assembled from segments of baseline totaling at least 2’ in the 10’ window
Excludes periods of accelerations, decelerations and hypervariability
Bradycardia is < 110 bpm
Tachycardia is > 160 bpm

32. Describing FHR Variability
Excludes accelerations, decelerations
Quantitated as peak-to-trough
Absent variability: amplitude undetectable
Minimal variability: amplitude detectable but ≤ 5 bpm
Moderate variability: amplitude 6-25 bpm
Marked variability: amplitude > 25 bpm

33. Describing Accelerations
Abrupt increase in FHR
Onset to peak < 30”
Peak: ≥ 15 bpm lasting 15” from onset to return to baseline
Prolonged acceleration: ≥ 2’ but < 10’
Acceleration > 10’ = baseline change

34. Describing Decelerations
Decrease in FHR associated with uterine contraction
Gradual decrease: onset to nadir ≥ 30”
Abrupt decrease: onset to nadir < 30”
Recurrent decelerations:
Occurs with ≥ 50% of UCs
Intermittent decelerations:
Occurs with < 50% of UCs

35. Classifying Decelerations
Onset
Shape
Nadir
Early
Gradual
Symmetrical
Matches UC peak
Variable
Abrupt
Asymmetrical
≥ 15 BPM LASTING ≥ 15” but < 2’
Late
After UC peak

36. Deceleration Features NOT Defined
Slow return to baseline
Biphasic decelerations
‘Reflex’ tachycardia following variable decelerations
Shoulders or overshoots
FHR fluctuations in the trough of the deceleration
Mild, moderate and severe

37. What to Call the Categories?
Problems
Limited evidence base
Litigation issues
Possible titles:
Normal, reassuring, non-pathological
Abnormal, pathological
Intermediate, suspicious, non-reassuring, atypical
Conference Decision:
Reassuring
Equivocal – requires ongoing assessment/evaluation;
Abnormal – requires urgent action

38. After Extensive Discussion:
Concerns about terms: normal, abnormal, equivocal
Concerns about implied action necessary (e.g., equivocal requires intervention).
Final Framework:
Category I
Category II
Category III

39. 3 Tier FHR Interpretation System: Category I
Category I FHR tracings include all of the following:
Baseline rate: bpm
Baseline FHR variability: moderate
Late or variable decelerations: absent.
Early decelerations: present or absent.
Accelerations: present or absent.

40. 3 Tier FHR Interpretation System: Category III
Category III FHR tracings include either:
Absent FHR variability and any of the following:
Recurrent late decelerations
Recurrent variable decelerations
Bradycardia
Sinusoidal Pattern for ≥ 20’

41. 3 Tier FHR Interpretation System: Category II
Category II FHR tracings includes all FHR tracings not categorized as Category I or Category III.
Represent an appreciable fraction of those encountered in clinical care.

42. 3 Tier FHR Interpretation System: Category II Examples
Moderate variability with bradycardia
Minimal FHR variability
Absent variability with no recurrent decels
Recurrent variable decels with moderate variability
Recurrent late decels with moderate variability

43. FHR Management Principles
Correlate with fetal acid-base status
Do NOT predict cerebral palsy
Are only relevant for the point in time referenced

44. FHR Categories: Meaning and Action
Category I
Normal
Strongly predictive of normal acid base status
Follow ‘in a routine manner’
Category III
Abnormal
Predictive of abnormal acid base
Prompt evaluation required
Resolve the pattern (support measures, delivery)

45. FHR Categories: Meaning and Action
Category II
Indeterminate
Not predictive of abnormal acid base status
Inadequate evidence to classify as Category I or III
Requires evaluation, continued surveillance and reevaluation