This document provides information on intrapartum fetal monitoring techniques including fetal heart rate monitoring, indications for continuous electronic fetal monitoring, interpretation of fetal heart rate patterns, and management of non-reassuring fetal status. It discusses techniques like intermittent auscultation, electronic fetal monitoring, fetal scalp pH testing, pulse oximetry, and lactate testing. The goal of intrapartum monitoring is timely identification and rescue of fetuses at risk for neonatal morbidity from hypoxic insult during labor and delivery.

1. DR. Mohit Satodia
DR.BHARTI GOEL

2. GOAL
 The timely identification and rescue of the fetus at risk
of neonatal and long term morbidity from
intrapartum hypoxic insult

3. Intrapartum monitoring

FHR monitoring –

Intermittent auscultation(IA)

Electronic fetal monitoring(EFM)
 Fetal Scalp pH
 Fetal Pulse oximetry
 Fetal scalp lactate testing
 ST waveform analysis

4. FETAL HEART RATE MONITORING
 External FHR monitoring-
 Hand-held Doppler ultrasound probe
 External transducer

5. External FHR monitoring-

6. TECHNICAL CONSIDERATIONS
 Basis for FHR monitoring is beat to beat recording
 For practical purposes ,this is possible only when
direct fetal electrocardiograms are recorded with a
scalp electrode.
 Paper speed is important. Commonly used are 1,2 or 3
cm/min.
 1 cm/min –a) good records for clinical purposes and
limiting the cost and amount of paper
b)crowding together of the record making
baseline variability difficult to interpret.

7. Contd…
 3 cm/min- a) useful when record is difficult to
interpret at slow speed i.e. during second stage of
labor
b) waste of paper more

8. Internal FHR monitoring Spiral electrode attatched to the fetal scalp with a
connection to FHR monitor.
 The fetal membranes must be ruptured, and the cervix
must be at least partially dilated before the electrode
may be placed on the fetal scalp.

9. Intermittent auscultation
 In uncomplicated pregnancies .
 Doppler better than stethoscope.
 Every 15 - 30 minutes in active phase of first stage and every 5
minutes in second stage
 Listen in the absence of active pushing and toward the end of the
contraction and at least for 30seconds after each contraction
ACOG JUlY 2009
CONTINUOUS EFM
 No benefit in low risk
 Continuous EFM -when risk factors for present
 Every 15 minutes in first stage and every 5 minutes during the
second stage.

10. Fetal Assessment : IA & EFM
Surveillence
Low-Risk
High-Risk
Pregnancies Pregnancies
Acceptable methods
Intermittent Auscultation*
Yes
Yes (a)
Continuous Electronic Fetal
Monitoring (EFM)
Yes
Yes (b)
First-stage Labour
30 min
15 min (a,b)
Second –stage labour
15 min
5 min (a,c)
Evaluation Intervals
•a- before, during and especially after a contraction for 60 sec
•b- includes evaluation of tracing every 15 min
• c- evaluation of tracing every 5 min
(ACOG & AAP 2007)

11. INDICATIONS FOR CONTINUOUS
EFM
Antepartum risk factors









Abnormal Doppler umbilical artery velocimetry
Suspected IUGR
APH
HTN / preeclampsia (current pregnancy)
DM
Multiple pregnancy
Uterine scar / previous CS
Iso-immunisation
Oligohydramnios / polyhydramnios
Maternal medical conditions(including severe anaemia, cardiac
disease, hyperthyroidism, vascular disease, renal disease)

12. Risk factors during labour Prolonged rupture of membranes (> 24 hours)
 Meconium-stained or blood-stained liquor
 Fetal bradycardia
 Fetal tachycardia
 Maternal pyrexia > 38 ˚C
 Chorioamnionitis
 Vaginal bleeding in labour
 Prolonged active first stage of labour (> 12 hours regular
uterine contractions with cervical dilatation>3cm)
 Prolonged second stage of labour .

13. Other indications
 Any use of oxytocin whether for induction or for
augmentation of labour
 Before and for at least 20 minutes after administration
of prostaglandin
 Epidural analgesia (immediately after inserting an
epidural block)

14. Benefits of EFM over IA Reduced risk of neonatal seizures(RR 0.50)
No benefit over IA did not reduce perinatal mortality(RR, 0.85)
 did not reduce the risk of cerebral palsy (RR, 1.74)
Risks of EFM High false-positive results.
 Increased rates of surgical intervention
 High interobserver and intraobserver variability
COCHRANE 2006

15. Electronic fetal monitoring
 Various components include
-Baseline
-Variability
-Accelerations
-Decelerations

16. External fetal monitoring
BASELINE
The mean FHR rounded to increments of 5 bpm during a 10minute segment, excluding:
—Periodic or episodic changes
—Periods of marked FHR variability
—Segments of baseline that differ by more than 25 bpm
 The baseline must be for a minimum of 2 minutes in any
10-minute segment
 Normal : 110–160 bpm
 Tachycardia: > 160 bpm
 Bradycardia: <110 bpm

17. FETAL HEART RATE MONITORING
 Baseline Variability
 Fluctuations in the baseline FHR that are irregular in
amplitude and frequency
 Visually quantitated as the amplitude of peak-totrough in bpm.
Absent—amplitude range undetectable
Minimal—0 to5 bpm
Moderate (normal) — 6to25 bpm
Marked—> 25 bpm

18.  Short term variability – small changes in fetal beat to
beat intervals under physiological conditions
 Long term variability- certain periodicity in the
direction and size of these changes causes oscillations
of fetal heart rate around mean level
 In FHR tracings short term variability is superimposed
over long term variability as minimal deflexions, not
interpreted by naked eye, therefore in clinical practice
variability means long term variability

19.  Long term variability characterized by – frequency and
amplitude
 Frequency is difficult to assess correctly
 Therefore , variability is usually quantitated by
amplitude of the oscillations around baseline heart
rate.

21.  The tracing shows an amplitude range of ~ 10
BPM (moderate variability ).

22. Factors affecting variability
 Normal variability : 98% fetuses not acidotic
 Decreased variability: Fetal metabolic acidosis , CNS
depressants, fetal sleep cycles, congenital anomalies,
prematurity, fetal tachycardia, preexisting neurologic
abnormality, betamethasone.
 Increased variability (saltatory pattern):Acute hypoxia
or cord compression, eg 2nd Stage

23. ACCELERATION
 A visually apparent abrupt increase in the FHR
 <32 weeks: >10 BPM above baseline for >10 sec
 >32 weeks: >15 BPM above baseline for > 15 sec
 Prolonged acceleration lasts >2 min but <10 min in
duration.
 If an acceleration lasts 10 min or longer, it is a baseline
change

24. Early Deceleration
 Symmetrical gradual decrease and return of the FHR
associated with a uterine contraction
 The nadir of the deceleration occurs at the same time
as the peak of the contraction.
 In most cases the onset, nadir, and recovery of the
deceleration are coincident with the beginning, peak,
and ending of the contraction, respectively

25. Caused by fetal head compression by
uterine cervix
Usually seen between 4 and 6 cm of
dilation

26. Late Deceleration
 Symmetrical gradual decrease and return of the FHR
associated with a uterine contraction
 The deceleration is delayed in timing, with the nadir of
the deceleration occurring after the peak of the
contraction.
 In most cases, the onset, nadir, and recovery of the
deceleration occur after the beginning, peak, and
ending of the contraction, respectively

27. Associated with uteroplacental insufficiency
Causes -Maternal hypotension,postmaturity, DM,HTN

28. Variable Deceleration
 Visually apparent abrupt decrease in FHR
 The decrease in FHR is ≥ 15 bpm , lasting ≥ 15 sec, and
<2 minutes in duration.
 When variable decelerations are associated with
uterine contractions, their onset, depth, and duration
commonly vary with successive uterine contractions.

29. Caused by compression of the umbilical cord.
If appearing early in labour-often caused by
oligohydramnios

30. TYPES
 Typical
 Atypical
 Loss of shoulders
 Slow return to baseline
 Prolonged secondary rise in baseline
 Loss of variability during deceleration
 Continuation at lower baseline

31. Classification of the severity of
variable deceleration
 MILD-
Deceleration of a duration of <30sec , regardless of
depth
Deceleration not below 80bpm , regardless of
duration
 MODERATE- Deceleration with a level <80bpm
 SEVERE- Deceleration to a level <70bpm for >60sec

32. Prolonged Deceleration
 Decrease from baseline that is 15 bpm or more, lasting
≥ 2 min but <10 min
 If lasts 10 minutes or longer, it is a baseline change
 Causes-prolonged cord compression,prolonged
uterine hyperstimulation,severe degree of
abruptio,eclamptic seizure,following conduction
anaesthesia

33. SINUSOIDAL PATTERN
 Visually apparent, smooth, sine wave-like undulating
pattern in FHR baseline with a cycle frequency of 3–5
per minute which persists for 20 min or more.
 Indicates
severe fetal anemia as occurs in
 Rh isoimmunization
 Feto maternal hemorrhage
 Twin twin transfusion syndrome
severe hypoxia

34. A

35. Three-Tiered Fetal Heart Rate
Interpretation System
Category I- NORMAL acid base status
• Baseline rate: 110–160 bpm
• Moderate Baseline FHR variability
• No Late or variable decelerations
• Early decelerations:
• Accelerations:
Category II-INDETERMINATE not categorized as Category I or III.
Category III-ABNORMAL acid base status-Intervention
• Absent baseline FHR variability and any of the following:
—Recurrent late decelerations
—Recurrent variable decelerations
—Bradycardia
• Sinusoidal pattern

37. RCOG CLASSIFICATION
BASELINE
VARIABILITY
DECELERATIO
N
REASSURING
110-160
≥ 5 bpm
None
NON
REASSURING
100-109
161-180
< 5 for ≥40 min
but <90 min
Early decel;
typical variable;
single prolonged
≤ 3min
ABNORMAL
<100
>180
sinusoidal ≥ 10
min
< 5 for ≥90 min
Late decel;
atypical variable;
single prolonged >
3min
ACCELERATIO
N
present

38.  Ancillary tests that can aid in the management of
Category II or Category III FHR tracings Four techniques are available to stimulate the fetus:
1)fetal scalp sampling,
2) Allis clamp scalp stimulation,
3) vibroacoustic stimulation, and
4) digital scalp stimulation

39.  A Cochrane review of three trials concluded that
manual fetal manipulation did not decrease NRFS and
it is not recommended.
 Cochrane review of two trials concluded that antenatal
maternal glucose administration did not decrease the
incidence of NRFS and it is not recommended.

40. Standard interventions for NRFS Supplemental oxygen
Discontinuation of any labor stimulating agent
Changing maternal position
Resolution of maternal hypotension-hydration.
P/V to determine umbilical cord prolapse, rapid
cervical dilation, or descent of the fetal head,ARM
Assessment of uterine contraction .
Tocolytics-in tachysystole with associated FHR
changes.
When the FHR tracing includes recurrent variable
decelerations -Amnioinfusion

42. MANAGMENT
Suspicious CTG If inadequate quality-check contact and connections
 If hypercontractility-discontinue oxytocin, consider
tocolytics
 Maternal tachycardia,pyrexia,dehydration, hypotension
 Supine? Epidural? sedation? drugs?
 i/v crystalloid bolus; 10 L/min O2
If persistent → do ancillary tests
Pathological CTG
 FBS if feasible
 If not feasible-expedite delivery (within 30 min)

43. Effects of Medications on FHR
Patterns
Narcotics decreased variability and accelerations
Corticosteroids Decreased variability (with beta-methasone but not dexamethasone)
Magnesium sulfate A significant decrease in short-term variability, clinically insignificant
decrease in FHR inhibits the increase in accelerations with advancing
gestational age
Epidural analgesia decreased variability and accelerations
Terbutaline Increase in baseline FHR

44. FETAL SCALP PH
 In women with "abnormal“ fetal heart rate tracings .
 Cervix needs to be 4-5cm dilated and Vx at -1 st or




below
pH <7.20 –fetal acidosis: deliver
pH 7.20-7.25 – borderline, repeat in 30 min or deliver if
rapid fall
pH > 7.25 – reassuring, repeat if FH abnormality
persists
Greater utility of scalp pH is in its high negative
predictive value (97–99%).

45.  Contraindications
 Maternal infection (HIV, hepatitis, HSV)
 Fetal bleeding disorders (e.g. haemophilia)
 Prematurity < 34 weeks
 Face presentation

47. FETAL PULSE OXIMETRY
 Acidosis: O2 sat. <30% for >2min
 Approved by FDA for use in fetuses with NRFS in May
2000
 The ACOG currently recommends against its use until
further studies are available to confirm its efficacy and
safety
 Insufficient evidence for its use as an adjunct or
independent of electronic fetal surveillance.

48. FETAL SCALP LACTATE TESTING
 Higher sensitivity and specificity than scalp pH
 > 4.8 mmol/L : acidosis
 Clinical trial that compared the use of scalp pH to
scalp lactate level did not demonstrate a difference in
the rate of acidemia at birth, Apgar scores, or neonatal
intensive care unit admissions
 Not recommended for routine use

49. ST WAVEFORM ANALYSIS
 Method: STAN S31 fetal heart monitor(USFDA)
Scalp electrodes
 The electrical fetal cardiac signal – P wave, QRS
complex, and T wave – is amplified and fed into a
cardiotachometer for heart rate calculation

50.  Restrict fetal ST waveform analysis to those with non
reassuring fetal status on EFM
 The use of ST waveform analysis for the intrapartum
assessment of the compromised fetus is not recommended
for routine use at this time.

51. THANK YOU