CTGInterpretation and management

Aboubakr Elnashar: Benha University Hospital, EgyptAboubakr Elnashar

INTERPRETATION

Steps

1. Evaluate tracing.

Do you have enough of a continuous strip for

interpretation

2. Identify

FHR baseline

BBV

absent, minimal, moderate or marked

Accelerations or

Decelerations.

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3. Evaluate contractions

regularity, rate, intensity, duration of

contractions.

4. Correlate accelerations and decelerations with

uterine contractions and identify the pattern.

5. Determine whether the FHR recording is

reassuring, non reassuring or ominous.

6. Document interpretation of

FHR

clinical conclusion

plan of care.

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STRUCTURED METHOD

The most popular structure can be remembered using the

acronym:

DR C BRA VADO = 7 items

1. Demographics of the patient

2. indication of CTG

3. Any obvious abnormalities

DR - Define Risk ? PET, diabetes, IUGR, smoker

C - Contractions - Frequency, duration, intensity, resting

tone

BRA - Baseline rate - 110-160bpm

V - Variability - 5-25 beats

A - Accelerations - 2 in 20 minutes

D - Decelerations - abnormal

O - Overall risk assessment Aboubakr Elnashar

Define Risk

• You first need to assess if this pregnancy is high or low risk

• This is important as it gives more context to the CTG

reading. e.g. If the pregnancy is high risk, your threshold for

intervening may be lowered

• Maternal medical illness

Gestational diabetes

Hypertension

Asthma.

• Obstetric complications

Multiple gestation

Post-date gestation

Previous cesarean section

Intrauterine growth restriction

Premature rupture of the membranes

Congenital malformations

Oxytocin induction/augmentation of labor

Pre-eclampsia. Aboubakr Elnashar

O – Overall assessment

Once you have assessed all aspects of the CTG

you need to give your overall impression

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Categorization of FHR traces

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II. MANAGEMENT

FIGO Fetal HR Pattern Classification

Normal means fetal health

• Suspicious means

- continue observation

- additional tests

• Pathological means

- additional test

- intervention

1. Normal/Reassuring

risk of fetal hypoxia in spontaneous labour is low:

Manage normally.

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2. Suspicious/Equivocal/ Non reassuring

continue EFM

Amniotomy should be performed

+/- fetal scalp blood pH if meconium stained

liquor is present.

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Initial Evaluation and Treatment of Nonreassuring

Fetal Heart Rate Patterns

Discontinuation of any labor stimulating agent

Cervical examination:umbilical cord prolapse or

rapid cervical dilation or

descent of the fetal head

Changing maternal position left or right lateral recumbent position:

reducing compression of the vena cava and improving

uteroplacental blood flow

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Monitoring BP

for evidence of hypotension, especially in those with

regional anesthesia

if present: treatment with ephedrine or phenylephrine

may be warranted

Assessment of patient for uterine hyperstimulation

by evaluating uterine contraction frequency and

duration

In the presence of abnormal FHR patterns and

uterine hypercontractility not secondary to oxytocin

infusion: tocolysis

subcutaneous terbutaline 0.25 milligrams

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In cases of suspected or confirmed acute fetal

compromise:

delivery should be accomplished as soon as

possible, accounting for the severity of the FHR

abnormality and relevant maternal factors

The accepted standard has been that ideally this

should be accomplished within 30 minutes.

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Maternal facial oxygen therapy

Prolonged use of maternal facial oxygen therapy

may be harmful to the fetus and should be avoided.

There is no research evidence evaluating the

benefits or risks associated with the short-term use

of maternal facial oxygen therapy in cases of

suspected fetal compromise .•C

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3. Abnormal/Pathological

Amniotomy

Fetal scalp blood pH if meconium stained

liquor to determine subsequent management

or

Deliver if clinically indicated.

Deliver if fetal scalp pH required but not

obtainable i.e. if cervix not sufficiently dilated

or equipment not available.

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III. SPECIAL SITUATIONS

Second Stage of Labour

Signs of hypoxia:

• Tachycardia

• ↓ variability between and during decelerations

• Late decelerations

• Failure to return to baseline (or > 100 bpm)

after decelerations

• Prolonged bradycardia

* Delay of 20 min → asphyxiated infant

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Placental abruption

• Uterine irritability shown by frequent

contractions of low amplitude

• FHR trace:

initially tachycardia

± decelerations

no accelerations

↓ variability.

Bradycardia is a late and danger sign of

severe asphyxia

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Fetal abnormality

• CNS abnormality: →

↓ baseline variability

low baseline rate

• Discrepancy between CTG (abnormal) and

biophysical profile (within normal) suggest

chromosomal abnormalities, especially if bony

measurements are reduced/slight IUGR

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Heart block

• Persistent bradycardia / double counting

• No respond to stimulation

Dying fetus

• Acute/subacute insult : decelerations /

tachycardia / lack of accelerations → ↓

variability → bradycardia

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Thank you

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CTG

PATTERN

CAUSE CLINICAL MANAGEMENT

Declaration

Early

2nd Stage NONE

Late Uterine

hypercontractily

Stop oxytocin

Consider terbutaline sc

Oxygen @ 8-10 l/min

Left lateral decubitus

Variable Cord

compression

Consider amnioinfusion

(mild/mod v.d.)

Tachycardia Maternal fever,

tachycardia,

dehydration

Infection screen

Hydrate: crystalloids

Stop tocolysis if pulse>120

SUSPICIOUS CTG

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PATHOLOGICAL

FETAL SCALP

BLOOD Ph

(If facilities available)

FETAL SCALP

STIMULATION TEST

FETAL VIBROACAUSTIC

STIMULATION TEST

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PATHOLOGICAL

FETAL SCALP

BLOOD Ph

(If facilities available)

FETAL SCALP

STIMULATION TEST

FETAL VIBROACAUSTIC

STIMULATION TEST

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Category Definition

Normal All four reassuring

Suspicious 1 non-reassuring

Rest reassuring

Pathological 2 or more non-reassuring

1 or more abnormal

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b)Abnormal/Pathological Trace- Baseline FHA> 150 bpm + silent pattern and/or repeated late or

variable decelerations- Silent pattern for >90 minutes- Complicated variable decelerations (depth >60 bpm for >60

seconds, changes in shape: over-shoot, decreased or increased baseline FHR following the decelerations, or absence of baseline variability in or between decelerations, slow recovery)

- Combined/biphasic decelerations (variable followed by late)- Prolonged bradycardia in a suspicious trace - Prolonged bradycardia> 10 minutes with no signs of recovery- Repeated late decelerations- Pronounced loss of baseline variability regardless of baseline

FHR with shallow late decelerations- Sinusoidal pattern with no accelerations

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a)Normal/Reassuring Trace- At least two accelerations (> 15 beats per minute

for >15 seconds) in 20 minutes - Baseline heart rate: 110-150 bpm - Baseline variability: 5-25 bpm- Early decelerations (in late first stage of labour)

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b)Suspicious/Equivocal Trace- Absence of accelerations for >40 minutes

(non reactive)- Baseline heart rate: 150-170 bpm or 100-110 bpm

(normal variability, no decelerations) - Silent pattern (<5 bpm for >40 minutes) although

normal baseline (110-150 bpm), no decelerations

- Baseline variability >25 bpm in the absence of accelerations

- Variable decelerations (depth <60 bpm, duration <60 seconds)

- Occasional transient prolonged bradycardia if FHR drops to <80 bpm for >2 minutes or <100 bpm For >3 minutes

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