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

A Reevaluation Workshop April 28-29-2008 ELECTRONIC FETAL HEART RATE MONITORING: A Reevaluation Workshop April 28-29-2008 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)

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

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

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

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

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

‘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

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

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

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

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

Courtesy of Dr. David James

Courtesy of Dr. David James

SOGC.org

Classification of intrapartum EFM tracings Normal tracing Previously “Reassuring” Atypical Tracing Previously “Non-reassuring” Abnormal Tracing Baseline 110-160 bpm Bradycardia 100-110 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 40-80 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.

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

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

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

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

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

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.

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

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).

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

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.

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

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

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

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

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

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

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

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

3 Tier FHR Interpretation System: Category I Category I FHR tracings include all of the following: Baseline rate:110-160 bpm Baseline FHR variability: moderate Late or variable decelerations: absent. Early decelerations: present or absent. Accelerations: present or absent.

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’

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.

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

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

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)

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