Aboubakr Elnashar

Aboubakr Elnashar

Fetal Neurodevelopment

Function Center Week

Tone cortex/subcortex 7.5-8.5

Movement

cortex/nucle 9

Breathing i ventral surface of fourth

ventricle

20-21

Fetal heart

rate

reactivity

posterior hypothalamus/

medulla

24

Aboubakr Elnashar

Patterns of foetal activity

1.Fetal breathing movements

2.Gross body movements

3.Fine motor movements

Aboubakr Elnashar

Fetal behavioral states

(Nijhuis et al, 1982):

• F1: quiescent state (quiet sleep)

• F2: Frequent gross body movements

• F3: Continuous eye movement. This state was disputed (Philia & James, 1990)

• F4: Vigorous body movements & FHR

accelerations

Aboubakr Elnashar

During the last 10 w of pregnancy:

F. breathing movements: 30% of the time

Gross body movements: 10% of the time

At term:

Cycling between activity & quiescence occurs

over a time span of 60 min

Activity is highest in late evening

FHR variation increases during fetal activity

Accelerations are associated with f. body

movements. Aboubakr Elnashar

Adaptations to hypoxia

Early

1.Reduced FHR reactivity

2.Absence of breathing movements

Late:

1. Reduced body movements and tone

2. Reduced liquor (renal hypoperfusion)

Aboubakr Elnashar

Aboubakr Elnashar

The ideal test 1. Quick

2. Easy to perform

3. Interpreted results that are

reproducible.

4. Clearly identify the compromised

fetus at a stage at which intervention

will improve the outcome

5. Not give an abnormal result for a

healthy fetus.

Unfortunately, this ideal test does not

yet exist!

Aboubakr Elnashar

I. Fetal movements counting (FMC)

II. Fetal heart rate recording 1.CTG

2.Non-Stress Test (NST)

3.Contraction StressTest (CST) or Oxytocin Challenge

Test (OCT)

4.Nipple stimulation test

5.Vibroacoustic stimulation (VAS)

6.Computerized CTG

III. Biophysical Profile (BPP)

IV. Doppler

Aboubakr Elnashar

I. Fetal movements counting

(FMC)

Idea:

Sadovsky and Yaffee (1973)

pre-eclamptic patients

noticed decreased

fetal movement prior to fetal demise.

Aboubakr Elnashar

Women perceive

most movement when lying down

fewer when sitting and

least while standing.

Busy pregnant women: not

concentrating on fetal activity: often

report a misperception of RFM.

Aboubakr Elnashar

important clinical sign:

significant reduction or sudden

change in movement

The fetus may be in a state of

sleep or the mother may be too

busy to focus on fetal activity.

Although fetal movements tend

to plateau at 32 w, there is no

reduction in the frequency of fetal

movements in the late 3rd

trimester.

Aboubakr Elnashar

How to perform?.

1.One to Two Hours Method.

The patient is asked to relax on her left side 30 min

after eating.

The patient should record the time that she starts the

test and note each time the baby kicks.

Normal: 3-5 Kicks within 60 min

Normal: 10 within 60-75 minutes.

Aboubakr Elnashar

Aboubakr Elnashar

2. The Cardiff Count-to-Ten

chart:

The patient records fetal

movements during the course of

usual daily activity.

warning signal:

12 hours without at least 10

perceived movements: patient

should be evaluated and should

undergo further testing e.g.

NST.

Aboubakr Elnashar

Advantages:

1. Inexpensive & noninvasive

2. An effective screening measure

{reductions in fetal mortality from

8.7 deaths per 1,000 live births to

2.1 deaths per 1,000 live births}.

Some authorities suggest that all

pregnant patients, regardless of risk

factors, be counseled about formal

assessment of fetal movement.

Aboubakr Elnashar

Disadvantages:

1. US studies:

mother can feel up to 80% of

movements seen on scan

after 36 w, a mother may feel

only 15% of movements.

2. No defined number of

movements that must be felt,

nor is it known over what time

frame the testing should occur.

Aboubakr Elnashar

3. Routine daily FMC followed by appropriate action

when movements are reduced offer no advantage

over informal inquiry about movements during

standard antenatal care & selective use of formal

counting in high risk cases{B}

(RCT of 68000 women).

4. Although the study did not rule out a beneficial

effect of FMC, the policy would have to be used by

1250 women to prevent one perinatal death.

Aboubakr Elnashar

Should fetal movements be counted routinely in a

formal manner?

insufficient evidence to recommend formal fetal

movement counting using specified alarm limits

(NICE)

Women should be advised to be aware of their

baby’s individual pattern of movements.

If they are concerned about a reduction in or

cessation of fetal movements after 28+0w, they

should contact their doctor. and should not wait

until the next day for assessment of fetal wellbeing.

Aboubakr Elnashar

The effect of FMC in high-risk pregnancies is not

known

Prudent

pay careful attention to their fetal movements.

reduction or an alteration in the movements of their

fetus should be offered some form of assessment

of fetal well-being [E].

Aboubakr Elnashar

II. Fetal heart rate recording

1.CTG

2.NST

3.Contraction stress test

4.Nipple stimulation test

5.Acoustic stimulation test

6.Computerized CTG

Aboubakr Elnashar

1. Fetal heart rate tracings (CTG) METHOD

Simultaneous recordings are performed by two

separate transducers,

one for FHR and

second one for UC

Aboubakr Elnashar

INTERPRETATION

1.Normal/Reassuring

Trace Baseline FHR: 110-150

b/m

Baseline variability: 10-25

b/m

At least 2 accelerations

(>15 beats for> 15 sec in

20 min)

No decelerations.

Aboubakr Elnashar

2. Suspicious/Equivocal Trace.

Baseline FHR: 150-170 b/m or 100-110 b/m

Reduced baseline variability (5-10 b/m for >40 m)

Absence of accelerations for >40 m

Sporadic deceleration of any type.

absence of

accelerations

diminished variability

late decelerations with

weak spontaneous

contractions.

Aboubakr Elnashar

Aboubakr Elnashar

Abnormal/Pathological Trace -

Baseline FHR: <100 b/m or > 170 b/m

Silent Pattern (<5 b/m) for >40 min

Sinusoidal pattern (oscillation frequency = 2-5

cycles/min, amplitude of 5-15 b/m) for >40 m

No accelerations

No area of normal baseline variability

Repeated

late,

prolonged (> 1 minute)

severe variable* (>40 b/m) decelerations. *decelerations vary in depth, vary in duration and vary in

timing relative to the uterine activity

Aboubakr Elnashar

Tachycardia

Sinusoidal pattern

Late deceleration

normal baseline rate at 120

bpm,

absent baseline variability,

no accelerations

late decelerations

Aboubakr Elnashar

variable fetal heart rate decelerations.

Reassuring shoulders (accelerations) are

obvious before and after each

deceleration.

baseline tachycardia

minimal variability. Aboubakr Elnashar

MANAGEMENT:

Normal/Reassuring Trace –

repeat and/or estimate AFI if considered necessary

acc to the clinical situation and indication for

testing.

Suspicious/Equivocal Trace –

Continue for up to 60 min {determine the presence

of fetal rest/activity cycles}.

Further evaluation acc to the cl situation e.g. fetal

acoustic stimulation, AFI, BPP, Doppler blood

velocity waveform.

Abnormal/Pathological Trace –

deliver if clinically appropriate.

Further evaluation/monitoring if not appropriate to

deliver. Aboubakr Elnashar

Advantages:

It is the most commonly

performed antenatal test for

fetal wellbeing.

Quick

Simple to perform

Aboubakr Elnashar

2. The Non-Stress Test (NST) (Hammacher et al, 1960)

Idea: • FHR accelerations:

linked closely with fetal movements

{increased sympathetic output}.

• The long term variability:

{balance between sympathetic & parasympathetic

tone}

• The short term variability (baseline or bandwidth

variability)

{parasympathetic tone}.

Aboubakr Elnashar

Steps:

1. left lateral recumbent position.

2. Place and adjust the external

tocodynamometer and US

transducer to obtain the best

possible tracing.

3. Instruct the patient to record f

movements on the monitor

tracing using the event marker.

4. Observe the EFM tracing until

the criteria for a reactive test are

met

(minimum of 20 min and maximum

of 60 min). Aboubakr Elnashar

In the event of lack of fetal movement, apply

stimulation e.g. fetal acoustic stimulator.

Record any relevant clinical information on the

EFM tracing e.g.

BP

T

P

loss of contact

changes in maternal position.

Aboubakr Elnashar

Interpretation: Reactive:

2 accelerations of FHR in 20 min.

Each acceleration 15 beat & lasts 15 sec.

Non-reactive:

no accelerations in 40 min.

Aboubakr Elnashar

•Reactive:

increase of FHR to >15 beats/min for

> 15 sec following fetal movements

Reactive

Aboubakr Elnashar

Antenatal maternal glucose administration:

not to reduce non-reactive CTG (Cochrane , 2001)

Manual fetal manipulation:

not to reduce the incidence of non-reactive CTG. (Cochrane , 2001)

Aboubakr Elnashar

Disadvantages: 1. Interpretation may be difficult &

poor agreement between experts

in assessing CTG

2. The predictive value of an abnormal

NST for perinatal morbidity &

mortality:<40% (Devoe et al, 1985)

Aboubakr Elnashar

3. No significant effect on perinatal

outcome

(MA of 13 trials)

Trend towards increased perinatal

mortality (SR of 4 RCT)

(Cochrane library, 2001)

NST should not be relied upon as

the sole means of establishing fetal

well-being {Ia}

Aboubakr Elnashar

3. The Contraction Stress Test (CST) or

Oxytocin Challenge Test (OCT)

1972: First introduced by Ray 1975: Freeman introduced the parameters of

contraction number and frequency to standardize

the test.

Aboubakr Elnashar

Idea: It is a test of the

uteroplacental unit.

If fetal oxygenation is

marginal at rest, it will

transiently worsen with uterine

contractions: hypoxemia: late

decelerations.

If variable decelerations

were seen, one should

suspect oligohydramnios. Aboubakr Elnashar

Steps: Semi-fowlers position.

If the patient is not having spontaneous

contractions, pitocin is begun at 0.5-1.0 mU and

increased /15-20 minutes until 3C/10 min.

Aboubakr Elnashar

Interpretation: Negative:

no decelerations with the 3 contractions in the

10 minute window.

Positive:

late decelerations with 50% or more of the

contractions.

Suspicious:

intermittent late decelerations or severe

variable deceleration.

Unsatisfactory:

<3 contractions or hyperstimulation. Aboubakr Elnashar

•Non-reactive NST followed by CST:

mild late decelerations.

Aboubakr Elnashar

CST: negative

Aboubakr Elnashar

1. Negative

No deceleration

2. Positive

transient

decelerations

Aboubakr Elnashar

Relative contraindications:

1. Preterm labor or certain patients at

high risk of preterm labor

2. Preterm membrane rupture

3. History of extensive uterine surgery or

classical cesarean delivery

4. Known placenta previa

Aboubakr Elnashar

The role of this technique has yet to be established

it has been associated with reports of fetal death

in cases of unrecognized severe fetal compromise

[E].

Aboubakr Elnashar

4. Nipple stimulation test

Intermittent nipple massage has the same goals.

How to perform

The women stimulate one breast, through their

clothes, for 2 min and then to rest for 5 min.

This cycle is repeated as necessary, but is interrupted

whenever contractions began.

Advantages

Hyperstimulation is not more frequent than

previously reported with CST.

Average time: 45 min.

Easy and quick method

Aboubakr Elnashar

Sequence Of Events With Placental Insufficiency or Hypoxia

1. Positive CST= late deceleration in 50% of UC.

2. Non reactive NST= No HR acceleration

3. Cessation of fetal movement

4. Basal line tachycardia > 160 bpm

5. Basal line bradycardia <110 bpm

Aboubakr Elnashar

5. VIBROACOUSTIC STIMULATION (VAS) Idea:

Vibroacoustic stimulator wakes a sleeping fetus:

changing its behavioral state.

How to perform:

Artificial larynxes that generate sound pressure levels

of approximately 80 to 100 decibels is applied in two

or three one-second bursts to the maternal abdomen

near the fetal head.

Aboubakr Elnashar

Advantages:

1. Easy, relatively inexpensive way to

shorten testing times and reduce the

false-positive rates for NST &

biophysical profiles.

2. Fetuses that respond to VAS with

an acceleration on NST or a startle

response on FBP: very low rates of

death within one week of the test.

3. Decrease the incidence of non-

reactive CTG and reducing the testing

time (The Cochrane Database of Systematic

Review, 2001)

Aboubakr Elnashar

6. Computerized CTG

• To improve the objectivity of antenatal CTG

• The program unlike conventional CTG, allows

measurement of short term variability (STV).

• STV=variation measured in 3.75 s epochs.

• FHRV: better predictor of fetal compromise than the

acceleration or decelerations.

• Likelihood of metabolic acidaemia or IUFD can be

calculated according to the STV.

Aboubakr Elnashar

Aboubakr Elnashar

Conventional Vs computerized CTG

1.Fewer additional fetal tests

2.Less time in testing.

3.The study was not large enough to

demonstrate any effect on perinatal morbidity

or mortality.

Aboubakr Elnashar

III. The Biophysical Profile (BPP)

First described by Manning in 1980.

Idea:

Sequence of fetal deterioration

1. Late decelerations appear (CST)

2. Accelerations disappear (NST, BPP, CST)

3. Fetal breathing stops (BPP)

4. Fetal movement stops (BPP)

5. Fetal tone absent (BPP)

6. Amniotic fluid decreases {chronic hypoxia: redistribution of

cardiac output away from the kidneys toward the brain}: AFV is

a quick evaluation of long term uteroplacental function as in the

late 2nd and all the 3rd trimester {AF is essentially fetal urine}.

Aboubakr Elnashar

OBSERVATION CRITERIA FOR PRESENT

CRITERIA FOR

NEGATIVE

Fetal Tone 1 episode of flexion-extension-flexion in 30 min

No episodes of flexion-

extension-flexion in 30

minutes

Fetal

Movement

3 gross body movements in30 min

Less than 3 gross body

movements in 30 minutes

Fetal

Breathing

1 episode of rhythmic breathing in 30 min

No episodes of rhythmic

breathing in 30 minutes

Amniotic Fluid

Volume

One 2 centimeter pocket measured in two perpendicular planes

A pocket measuring

less than 2

centimeters

NST Reactive test Non-reactive test

Two points are given if the observation is present and zero points are given if it is

absent. Aboubakr Elnashar

Interpretation: 8:

reassuring.

6:

equivocal: repeat within 24 h.

4 or less:

positive test: strongly suggests preparing the

patient for delivery.

Aboubakr Elnashar

Modifications

1. BPP Manning (1990)

NST

AFV

Fetal breathing.

less cumbersome

results are just as predictive.

Aboubakr Elnashar

2. Placental grading has been incorporated in the BPP to give an

overall score out of 12 rather than 10.

Aboubakr Elnashar

3. The most powerful components: •AFI: indicator of long term uteroplacental function

•NST: short term indicator of fetal acid-base status.

assessment of fetal well-being using these two

tools alone may well be as effective as formal BPP

Aboubakr Elnashar

Advantages:

1. In high-risk:

observational studies: effective

{good negative predictive value

(99.9%) i.e. fetal death is rare in

women with a normal FBP

rarely abnormal when Doppler

findings were normal}.

Aboubakr Elnashar

2. In pre-labour rupture of the

membranes

{fetal breathing movements is

reduced in the presence of

chorioamnionitis}

But sensitivity for abnormal BPP in

the presence of chorioamnionitis is

25%[B]: value of BPP is limited

Aboubakr Elnashar

Disadvantages:

1. Difficult and time-consuming

2. False-positive rate: 70%: increased rates of unnecessary intervention.

3. Systematic review of five RCTs: failed to demonstrate any significant benefit of BPP on pregnancy outcome when compared to NST

Aboubakr Elnashar

4. In low risk: cannot be recommended for routine monitoring

5. In high Risk: positive predictive value of 35% (observational study)

No enough evidence from RCTs

(Cochrane Systematic Review, 2000).: cannot be recommended for routine monitoring for primary surveillance in SGA

Aboubakr Elnashar

Statistical Characteristics of Selected

Antepartum Fetal Tests

Characteristic NST CST BPP

Specificity Poor Average High

Specificity High High High

False-positive rate High High High

False-negative rate Low Low Average

Aboubakr Elnashar

V. Doppler A. Umbilical artery Doppler

Idea: Umbilical Arterial Flow is normally of low resistance.

In hypoxic states:

relative placental hypoxia:

reactive VC of umbilical artery:

higher resistance:

decrease in diastolic flow

Aboubakr Elnashar

Doppler indices

Aboubakr Elnashar

Interpretation:

Resistance index

Enddiastolic flow

Systolic/diastolic ratio

Pulsatility index

Diastolic average ratio

Aboubakr Elnashar

•Resistance index:

Best ability to predict abnormal outcomes

(RCOG,2002 Evidence level II)

Normal pregnancy: {progressive increase in end-diastolic velocity

{growth& dilatation of the umbilical circulation}:

Resistance index falls.

Fetal growth restriction and/or PET: > 0.72 is outside the normal limits from 26 w.

Aboubakr Elnashar

•End Diastolic flow

In fetal growth restriction and/or preeclampsia:

reduced, then

absent (AED) or

reversed (RED) in severe cases

Absent or reversed:

Fetal distress is almost certain:

Immediate BPP or NST or

Delivery may be indicated.

Aboubakr Elnashar

•S/D

Should be <3.

Small increases in S/D= 3-5:

chronic intrauterine disease manifest by

IUGR.

Not strictly useful:

{1. low sensitivity.

2. Gestation age dependent}.

Aboubakr Elnashar

Normal

Absent

Reversed

Aboubakr Elnashar

RED

Aboubakr Elnashar

Absent

Reversed

Aboubakr Elnashar

Advantages:

1. In low risk

No benefit on mother or baby

(The Cochrane Library, 2003)

Aboubakr Elnashar

2. In high risk:

Reduction of

perinatal morbidity and mortality

number of antenatal admissions

inductions of labor

resources compared with CTG

(Grade A RCOG, 2002; The Cochrane Library, 2003)

Comparing FHR monitoring, FBP and umbilical

artery Doppler:

only umbilical artery Doppler had value in predicting

poor perinatal outcomes in SGA

Aboubakr Elnashar

Frequency of monitoring in SGA fetuses with

normal Doppler:

A 4-week U/S measurement interval was shown to

be superior to a 2-week interval, in terms of reducing

the false –positive rate (Owen et al, 2001).

Once/2w (Fortnightly) scans should be undertaken

where

1. linear growth velocity is not maintained or

2. AC is below the third centile (IV)

Aboubakr Elnashar

B. Middle cerebral artery peak systolic velocity

(MCA-PSV)

The most significant breakthrough in the

surveillance of the potentially anemic fetus

Based on:

In fetal anemia:

Enhanced fetal cardiac output and

Decrease in blood viscosity:

Increased blood flow velocity

preferentially shunt blood to brain faster

most pronounced MCA PSV

Aboubakr Elnashar

Frequency

•Initiated: 18 w

•Repeated: every 1–2 w as the clinical situation

MCA waveforms in an anemic fetus

requiring serial transfusions for severe Rh

(D) disease.

The peak systolic velocities of 62, 50, and

61 cm per second (top to bottom)

corresponded to fetal hematocrits of 19%,

44%, and 32%, before, at the time of, and a

week after the first intravascular

transfusion, respectively.

Aboubakr Elnashar

Aboubakr Elnashar

Advantage

More sensitive for predicting

f anemia than the ΔOD450 (Recent studies)

Alternative to serial

amniocenteses

Excellent noninvasive tool

for the monitoring of f anemia.

Aboubakr Elnashar

c. Uterine artery Doppler

limited use in predicting FGR and perinatal

death (Grade A, RCOG,2002).

Abnormal uterine artery suggest:

maternal cause for the growth restriction

Normal uterine artery Doppler suggest:

fetal cause

Aboubakr Elnashar

UAD: Normal

UAD: notch, decreased diastolic flow

Aboubakr Elnashar

Prediction of preeclampsia

(Uterine Doppler velocimetry)

Persistence of a

Diastolic Notch in

uterine artery

waveform after 24 w

Systolic/diastolic ratio

>2.6

RI > 0.58 after 24

weeks.

Systole

Diastole

Aboubakr Elnashar

Conclusions

Aboubakr Elnashar

1. CTG, must not form the sole basis for the

assessment of the fetus.

2. Computerized CTG may well be more effective

than standard CTG.

3. Formal assessment of the BPP does not

appear to hold any advantage over

assessment of liquor volume alone.

4. Where fetal growth restriction is suspected,

fetal biometry and assessment of umbilical

artery waveforms by Doppler ultrasonography

should be incorporated.

Aboubakr Elnashar

Aboubakr Elnashar Aboubakr Elnashar