FETAL MONITORING - PowerPoint Presentation

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FETAL MONITORINGANTE AND INTRAPARTUM

DR. OSHINOWO

M.B;B.S, FRCOG

OBSTETRICIAN/GYNAECOLOGISTSlide2

INTRODUCTION

The aim of ANC

Ensure maternal well being

Ensure Fetal well being

Identifying risks factors

Monitoring of certain parameters

ie

Weight, BP, Urinalysis, Blood sugar (if necessary)Slide3

ANTEPARTUM

PHYSICAL

BIOCHEMICAL

ELECTRONICSlide4

PHYSICAL

FUNDAL HEIGHT

SMALL FOR DATE

OLIGOHYDRAMNIOS

IUGR

IUD

LARGE FOR DATE

MULTIPLE GESTATION

POLYHYDRAMNIOS

FIBROIDSSlide5

ULTRASONOGRAPHY

Comes in 2D, 3D and recently 4D modes

Demonstrates features like Fetal anatomy, fetal weight, fetal movement, placental location, amniotic fluid volume

Helpful in specialized procedures like amniocentesis, Chorionic

villus

sampling, Biophysical profile, Fetal

doppler

, Fetal echocardiogram etcSlide6

GROWTH ULTRASOUND

Performed every 3 to 4 weeks

Fetus at risk of fetal growth restrictions secondary to medical conditions of pregnancy or fetal abnormalitiesSlide7

FETAL MOVEMENT ASSESSMENT

Normal: 10 movements/fetal kicks in 12 hours (Cardiff count to ten)

Decreased

fetal movement may precede fetal death by days

Mothers

should be encouraged to keep a FKC especially in high risks patientsSlide8

NON STRESS TEST (NST)

Assesses fetal movements with FHR acceleration

Reactive/Reassuring NST: 2 or more FHR accelerations at least 15 bpm above the baseline lasting at least 15

secs

in a 20

mins

period

Non reassuring NST may suggest fetal acidosis

What to do depends on gestational ageSlide9

BIOPHYSICAL PROFILE (BPP)

Composes of 5 components

Non stress test (NST)

Amniotic Fluid Volume (vertical pocket of 2cm or more)

Fetal breathing movements (30

secs

or more in 30

mins

)

Fetal movements (3 or more in 30

mins

)

Fetal tone (Extension/Flexion of an extremity)

Each carry a score of 2 points, a total of 8 or 10 is Normal, 6 is Equivocal, and 4 or less is abnormalSlide10

MODIFIED BIOPHYSICAL PROFILE

Combines Non stress Test + Amniotic Fluid Index (AFI)

AFI is measured by dividing the uterus into 4 quadrants and measuring the largest vertical pocket in each quadrant; the result summed up in millimeters

A nonreactive NST + AFI less than 50mm requires further interventionSlide11

CONTRACTION STRESS TEST (CST)

Rarely used today

Measures the response of Fetal HR to contractions

The test requires 3 contractions in 10

mins

A positive or Abnormal test results in decelerations in more than half of the contractions

Negative result: no deceleration with the contractions

Contraindication : Any case where

labour

not allowedSlide12

DOPPLER STUDIES

Assesses multi-vessel evaluation of fetal status

Can be used to assess a compromised fetus

i.e

growth restriction

Functions as a diagnostic tool that alerts the clinicianSlide13

INTRAPARTUM FETAL MONITORINGSlide14

Baseline

Fetal

H

eart

R

ate

(FHR)

Is

the mean level of the FHR when this is stable, excluding accelerations and

decelerations

It is determined over a time period of 5-10 minutes, expressed as beats per minute (

bpm)

NOTE:

Preterm

fetuses tend to have values towards the upper end of the normal range

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Basic Features of FH Trace

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Baseline Variability

Is the minor fluctuation in baseline FHR

It is assessed by estimating the difference in bpm between the highest peak and lowest trough of fluctuation in one minute segments of the trace

Uterine activity Normal variability is reassuring Sign that fetus nervous system is intact

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Baseline variability CTG

Baseline variability

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2

types of Variability

Short- Term variability or Beat to Beat variability

Is the difference between successive heartbeats or the moment

Long Term Variability

Is wider fluctuations

Over one (1) minute that causes wavy appearance in the monitor

Absent - No fluctuation Minimal - 5 bpm or less Moderate/Normal – 5bpm to 25

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Accelerations

Are transient increases in FHR of 15bpm or more above the baseline and lasting 15 seconds.

Accelerations in preterm fetuses may be of lesser amplitude and shorter duration

.

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Decelerations

Are

transient episodes of decrease of FHR below the baseline of more than 15 bpm lasting at least 15 seconds, which are:

Early

, Variable and Delayed

Time

relationships with contraction cycle may be variable but most commonly occur simultaneously with contractions

.

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EFM Decelerations

Decelerations-

transient slowing of

FHR below the

baseline level of

more than 15 bpm

and lasting for 15 sec.

Or more.

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Early

Deceleration

Uniform,

repetitive decrease of FHR with

slow onset early in the contraction and

slow return to baseline by the end of the contraction

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Fig 3 Early Decelerations

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Late decelerations

Uniform, repetitive decreasing of FHR with, usually,

slow onset mid to end of the contraction and

nadir more than 20 seconds after the

peak of the contraction and ending after

the contraction

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Fig 4 Late Decelerations

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Variable Deceleration

Repetitive or intermittent decreasing of FHR with rapid onset and recovery

Variable onset

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Fig 5 Variable Decelerations

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Prolonged Decelerations

Decrease of FHR below the baseline of more than 15 bpm for longer than 90 seconds but less than 5 minutes

Is pathological when crosses 2 contractions

i.e

3

mins

Reduction in Oxygen transfer to placenta

Associated with poor neonatal outcome

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Fig 6 Prolonged Deceleration

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Prolonged

Decelerations

CAUSES

Cord prolapse.

Maternal hypertension

Uterine Hypertonia

Followed by a VE or ARM or SROM with High presenting part

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Normal antenatal CTG trace

The normal antenatal CTG is associated with a low probability of fetal compromise and has the following features:

Baseline fetal heart rate (FHR) is between 110-160 bpm

Variability of FHR is between 5-25 bpm

Decelerations are absent or early

Accelerations x2 within 20 minutes

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Non-reassuring

CTG trace

Is where any of the following is present:

The presence of two or more features is considered abnormal as these may be associated with fetal compromise and require further action

Baseline FHR is between 100-109 bpm or between 161-170 bpm

Variability of FHR is reduced (3-5 bpm for >40 minutes)

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Abnormal CTG trace

The following features are very likely to

be associated

with significant fetal compromise and require further

action-

Two of the features described in non-reassuring CTG trace are present, OR

Baseline FHR is <100 bpm or >170 bpm

Variability is absent or <3 bpm

Variability is

sinusoidal

Decelerations are prolonged for >3 minutes / late / have complicated variables

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Process

Preparation

Determine indication for fetal monitoring

Discuss fetal monitoring with the woman and obtain permission to commence

Perform abdominal examination to determine lie and presentation

Give the woman the opportunity to empty her bladder

The woman should be in an upright or lateral position (not supine)

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Process Preparation

Check the accurate date and time has been set on the CTG machine, and paper speed is set at 1cm per

minute

CTGs must be

labelled

with the mother’s

name, her

number and date / time of commencement

Maternal

heart rate must be recorded on the CTG at commencement of the CTG in order to differentiate between maternal and fetal heart rates

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ASSESSING THE CTG USING DR C M BRAVADO

Determine risk

if the woman is a high or low obstetric risk. This sets the background for the interpretation

C

Assess the frequency and quality of

Contractions

per 10 minutes.

M

Assess fetal

Movements

, presence of

Meconium

and

Maternal

observations

Bra

Determine

Baseline Rate

and compare with earlier rate if possible.

V

Assess baseline

Variability

, is it normal, increased or reduced.

A

Are

Accelerations

present in response to fetal movements or contractions

D

If

Decelerations

are present, what are their characteristics.

O

Give an

overall

classification for the CTG

Normal

Suspicious

Pathological

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FETAL SCALP BLOOD SAMPLING

Useful in the presence of a non reassuring CTG

A scalp blood sample for pH or lactate determination

Specificity is high ( A normal value rules out asphyxia)

The sensitivity and positive predictive value of a low scalp pH in identifying a newborn with Hypoxic-

ischaemic

encephalopathy is lowSlide38

FETAL PULSE OXIMETRY

Measures fetal oxygenation during

labour

It is performed using a sensor placed

transcervically

against the fetal cheek

Normal values btw 35% and 65%

Metabolic acidosis develops when the value falls below 30% for at least 10-15

minsSlide39

CONCLUSION

The well being of any pregnancy begins pre-conception with adequate

counselling

of mothers with medical conditions

Pregnancy monitoring begins early in the gestation

Early and frequent prenatal care allows the care provider to screen the population to identify pregnancies at risk,

afterallSlide40

“

A NORMAL DELIVERY IS ONE IN WHICH THE MOTHER AND THE BABY ARE IN GOOD CONDITION REGARDLESS OF THE MODE OF DELIVERY

”Slide41

THANK YOU FOR LISTENING