Scott A Sullivan MD MSCR
Maternal-Fetal Medicine
MUSC
October 12, 2010
Disclosures
 I have no disclosures or conflicts to report
Disclosures – I am from MUSC!
Learning Objectives
 Discuss NICHD Consensus Recommendations
 Review fetal physiology and EFM patterns
 Alternate technology – what works, what doesn’t and
what is coming
A bit of history…
 Marzac – 1620 First description of fetal heart tones
 Killian – 1640 Theory that heart tones = fetal health
 Kergaradec – 1818 Technique, viability
 Kennedy – 1833 Intra-partum monitoring
 Von Winkel – 1893 “Fetal Distress” definitions
 DeLee / Hillis – 1922 Fetoscope
 Matthews – 1940 Amplified fetoscope
Edward H Hon, MD
1915 – 2009
Father of modern EFM
1958
First Viable EFM
1968 – Commercially
available
1972 – First scalp
electrode
1970’s – Coins
deceleration terms
1975 – 20 % of labors
used EFM
EFM – Antepartum Testing
 Reactivity translates to a fetal death rate of < 5 /1000
 Non-reactivity = fetal mortality rate of 40/1000
 False positive rate 50-97(!) %
 Unless ominous, requires a confirmatory test
Perinatal Death Rate
PMR / 1000 live births
50
45
40
35
30
25
20
15
10
5
0
PMR
1940
1960
1980
2000
Use of Intra-partum EFM in the US
90
80
70
60
50
% Use
40
30
20
10
0
1975
1985
1995
2004
So How Have We Done?
 1975 – 2010
 Decreased fetal death incidence
 Cesarean section rate increased 110 %
 Cerebral palsy incidence unchanged
 Lawsuit rate / live-birth rate increased 340 %
EFM vs. IA
 Cochrane Review – 2001
 9 RCTs
 18,561 patients
 No difference in Apgars, NICU, fetal death and
cerebral palsy
 Reduction in seizures (RR 0.51 0.32-0.82)
 Increases in C/S and OVD
Vintzileos – EFM vs IA
 1995
 Decrease in perinatal mortality (1/1000)
 1996
 Sensitivity – 97 % vs. 34 %
 Specificity – 84 % vs. 91 %
 PPV – 34 % vs. 22%
 NPV – 99.5 % vs. 95 %
What’s the Problem?
 Subjective interpretation
 Technological limitations
 Lack of interventional guidelines
 Confusing terminology
Terminology
 Gabbe vs. Williams
 “Short-Term”, “Beat to
Beat”
 Lack of inter-rater
reliability
 1997 Consensus
Inter-rater reliability
 4 OBs – 22 % agreement (Nielson)
 2 months later, re-reviewed
 25 % changed their own interpretation
 5 Obs – 29 % agreement (Beaulieu)
NICHD Conference
 2008
 Series of meetings
 Jointly published in
OBG, Pediatrics,
Neonatology
OBG 112(3);Sept 2008 661-666
Category I
 Must include ALL :
Baseline 110-160
Moderate variability
No late decelerations
Early decelerations +/Accelerations +/-
Category I
Category I
 “Normal”
 “Highly Predictive of a normal fetal pH”
 No Action Required
Physiology – Cat. I
Physiology – Cat I
Category III
 Absent variability, plus either
Recurrent late decelerations
Recurrent variable decelerations
Bradycardia
 Sinusoidal pattern
Category III
Category III
 “Abnormal”
 “Predictive of abnormal acid-base status”
 Requires prompt intervention or delivery
MANAGEMENT OF Cat III
 Discontinued oxytocin
 Begin oxygen 5-6 L/min
 Correct maternal hypotension
 Trendelenberg position
 Increase IV fluids
 Vasopressor (ephedrine 15 mg IV)
 Assess maternal oxygenation and acid/base status
 Terbutaline 0.25 mg SQ for in-utero resuscitation
Environment
Oxygen transfer can be disrupted at any of
these points and can manifest as FHR
deceleration (variable, late, prolonged)
Lungs
Heart
Vasculature
Uterus
Placenta
The degree of oxygen disruption is the
important factor, not the point in the
pathway at which oxygen transfer is
disrupted
Cord
Oxygen transfer
Fetus
Hypoxemia
Hypoxia
Metabolic acidosis
acidemia
Fetal response
Hypotension
Potential
Injury
DECREASED UTEROPLACENTAL
OXYGEN TRANSFER TO THE
FETUS
Chemoreceptor Stimulus
Alpha Adrenergic Response
With
Acidemia
Fetal Hypertension
Baroreceptor Stimulus
Myocardial
Depression
Parasympathetic Response
Deceleration
Without
Acidemia
Category II
 “Everything that not categorized as either Category I
or III”
 Examples : Tachycardia, bradycardia with normal
variability
 Absent variability, marked variability
 Lates + variability, unusual variables
Category II
Category II
 Category II FHR tracings are considered
“indeterminate”
 Not predictive of abnormal fetal acid-base status but
inadequate evidence to classify as Category I or III
 Requires evaluation and in-utero treatment if
appropriate
 Requires continued surveillance and re-evaluation in
context of clinical circumstances
Variability
 Moderate FHR variability is HIGHLY predictive of the
absence of metabolic acidemia at the time it is
observed
Parer JT J Maternal Fetal Neonatal
Med 2006; 19:289-94
Low JA Obstet Gynecol 1999;
93:285-91
Williams KP Am J Obstet Gynecol
2003; 188:820-3
Elimian A Obstet Gynecol 1997;
89:373-6
MINIMAL OR ABSENT FHR
VARIABILITY
 CNS depressants: Narcotics, Barbiturates, Benzodiazapines, Sedatives,
Alcohol
 Parasympatholytics: Phenothiazines, Atropine
 General anesthetics
 Magnesium sulfate
 Fetal tachycardia due to maternal fever or fetal infection
 Preexisting neurological injury
 Fetal acidosis/acidemia
NICHD 2008 - Pros
 Simple
 Better than 1998
 More widely adopted
 ACOG buy-in
NICHD 2008 - Cons
 No evidence the system is actually better
 Lack of actionable recommendations
 Category II ??
 Does not fix problems of EFM
A word about contractions
 Normal
≤ 5 contractions / 10 m
 Tachysystole
≥ 5 contractions / 10 m
 No hyperstimulation!
How About < 32 weeks?
 No clear recommendations
 < 28 weeks, 50 % will be non-reactive
 28-34 weeks, 15 %
 “10 x 10”?
VAS?
 Artificial larynx used to




stimulate the fetus
Shortens time to reactivity
9.9 minutes
88 dB in the uterus
Appears to be safe
Reactive NST is just as
reliable ?
What’s New?
 It’s clear we need something
better
 Fetal Pulse-Oximetry
 STAN
Fetal Pulse Oximetry
 Same technology
 Oxygen saturation
 Mechanical problems
FPO – Cochrane Review
 2007
 5 trials
 7424 subjects
 Overall no decrease in cesarean rate, seizures
 Fetal scalp sampling?
East CE, Cochrane Database 2007
STAN
 ST Waveform Analysis
 Automated analysis of
ST segments
 Uses EFM + ST
 FDA approved - 2005
2001 Lancet - STAN
 Sweden RCT
 4966 subjects
 STAN vs EFM alone
 Decrease in acidosis [RR 0.47 0.25-0.81]
 Decrease in OVD [RR 0.83 0.69-0.99]
Amer-Wehlin, Lancet 2001
2006 BJOG - STAN
 RCT
 1493 subjects
 Similar design
 No difference in acidosis
 No difference in cesarean section or OVD
Ojala K, BJOG 2006
STAN – Cochrane Review
 2006
 4 trials, 9829 subjects
 No difference in C/S, OVD
 Decreased acidosis [RR 0.64 0.41 – 0.99]
 Decreased HIE [RR 0.33 0.11-0.91]
 Insufficient evidence to recommend
Neilson, JP Cochrane Database
2006
Newer things….
 Doppler?
 WAS – 2009
 ANBLIR – 2010 (fuzzy logic, ANN)
 NIR photopleythysmography
What does ACOG Say?
 Practice Bulletin 106
 Endorses terminology
 High risk women need
continuous EFM, for
others it is optional
 No to FPO
Thank You