Fetal Assessment

Prof. Z. Babay

Screening for high risk pregnancy

History• *Age

•*Social burden•*Smoking

•*Past medical conditions e.g D.M, HTN•*Past Obstetric history

Fetal assessment

Aim: Ensure fetal wellbeing ( Identify patients at risk of fetal asphyxia)

To prevent prenatal mortality & morbidity

When to start fetal Assessment

**Risk assessed individually**For D.M. fetal assessment should start from 32

weeks onward if uncomplicated***If complicated D.M. start at 24 weeks onward

**For Post date pregnancy start at 40 weeks**For any patient with decrease fetal movement

start immediately **Fetal assessment is done once or twice weekly

FETAL AND NEONATAL COMPLICATIONS OFANTEPARTUM ASPHYXIA

Fetal Outcomes Neonatal Outcomes

Stillbirth MortalityMetabolic acidosis at birth Metabolic acidosisHypoxic renal damageNecrotizing enterocolitisIntracranial haemorrhageSeizuresCerebral palsy

CONDITIONS ASSOCIATED WITH INCREASEDPERINATAL MORBIDITY/MORTALITY WHEREANTENATAL FETAL TESTINGMAY HAVE AN IMPACT

Small for gestational age fetusDecreased fetal movementPostdates pregnancy (>294 days)Pre-eclampsia/chronic hypertensionPre-pregnancy diabetesInsulin requiring gestational diabetesPreterm premature rupture of membranesChronic (stable) abruption

Fetal AssessmentFetal movement countingNon stress test

Contraction stress test

Ultrasound fetal assessment

Umbilical Doppler Velocimetry

Fetal movement counting

Cardiff technique:*Done in the morning, patient should

*calculate how long it takes to have 10 fetal movement

**10 movements should be appreciated in 12 hours

Fetal movement counting

Sadovsky technique:-For one hour after meal the woman should

lie down and concentrate on fetal movement

-4 movement should be felt in one hour-If not , she should count for another hour

-If after 2 hours four movements are not felt, she should have fetal monitoring

Non stress test

*Done using the cardiotocometry with the patient in left lateral position

**Record for 20 minutes

Non stress test

*The base line 120-160 beats/minute*Reactive:

At least two accelerations from base line of 15 bpm for at least 15 sec within 20 minutesNon reactive:

No acceleration after 20 minutes- proceed for another 20 minutes

Non stress test

If non reactive in 40 minutes---proceed for contraction stress test or biophysical profile

The positive predictive value of NST to predict fetal acidosis at birth is 44%

NST

NST

Contraction stress test

Fetal response to induced stress of uterine contraction and relative placental insufficiency

Should not be used in patients at risk of preterm labor or placenta previa

Should be proceeded by NST

Contraction stress test•Contraction is initiated by nipple

stimulation or by oxytocin I.V.•

•The objective is 3 contractions in 10 minutes

•If late deceleration occur-----positive CST

Interpretation of CTG

Normal Baseline FHR 110–160 bpm –Moderate bradycardia 100–109 bpm –Moderate tachycardia 161–180 bpm –Abnormal bradycardia < 100 bpm –Abnormal tachycardia > 180 bpm

Acceleration

Deceleration

•EARLY : Head compression

•LATE : U-P Insufficiency

•VARIABLE : Cord compression Primary CNS

dysfunction

Early deceleration

Late deceleration

Variable Deceleration

Reduced Variability

TachycardiaHypoxia

ChorioamnionitisMaternal fever B-Mimetic drugs

Fetal anaemia,sepsis,ht failure,arrhythmias

Ultrasound fetal assessment

•Assessment of growth

•Biophysical profile (BPP)

Assessment of fetal growth by ultrasound

Biometry:Biparietal diameter (BPD)Abdominal Circumference (AC)Femur Length (FL)Head Circumference (HC)Amniotic fluid

•Placental localization

BPD

BPD & HC

Abdominal circumference

FL

Growth chart

Placental localization

Placenta previa

Amniotic fluid

Fetal Biophysical profileBiophysical Variable

Normal (score=2)Abnormal (score= 0)

Fetal breathing movements

1 episode FBM of at least 30 s duration in 30 min

Absent FBM or no episode >30 s in 30 min

Fetal movements3 discrete body/limb movements in 30 min2 or fewer body/limb movements in 30 min

Fetal tone1 episode of active extension with return to flexion of fetal limb(s) or trunk. Opening and closing of the hand considered normal tone

Either slow extension with return to partial flexion or movement of limb in full extension Absent fetal movement

Amniotic fluid volume

1 pocket of AF that measures at least 2 cm in 2 perpendicular planes

Either no AF pockets or a pocket<2 cm in 2 perpendicular planes

Test Score ResultInterpretationManagement

10 of 108 of 10 (normal fluid)8 of 8 (NST not done)

Risk of fetal asphyxia extremely rare

Intervention for obstetric and maternal factors

8 of 10 (abnormal fluid)Probable chronic fetal compromise

Determine that there is functioning renal tissue and intact membranes. If so, delivery of the term fetus is indicated. In the preterm fetus less than 34 weeks, intensive surveillance may bepreferred to maximize fetal maturity.

6 of 10 (normal fluid)Equivocal test, possiblefetal asphyxia

Repeat test within 24 hr

6 of 10 (abnormal fluid)Probable fetal asphyxiaDelivery of the term fetus. In the preterm fetus less than 34 weeks, intensive surveillance may be preferred to maximize fetal maturity

4 of 10High probability of fetal asphyxia

Deliver for fetal indications

2 of 10Fetal asphyxia almost certain

Deliver for fetal indications

0 of 10Fetal asphyxia certainDeliver for fetal indications

Umbilical Doppler Velocimetry

Indication:IUGRPETD.M.

Any high risk pregnancy

Use a free loop of umbilical cord to measure blood flow in it

Umbilical cord

Umbilical Artery Doppler

Umbilical cord doppler

Reverse flow in umbilical artery

Management of abnormal Doppler

Depends on:• fetal maturity

• gestational age•Obstetric history

Management of Doppler results

Reverse flow or absent end diastolic flow--- Immediate delivery

High resistance index---- repeat in few days or delivery

Normal flow---- repeat in 2 week if indicated

Assessment for chromosomal abnormality

•Ultrasound•Amniocentesis

•Chorionic villus sampling

Assessment for chromosomal abnormality•General Facts:

• The general incidence of Down is 1:1000• The risk by maternal age: at the age of 35 -----------1:365 at the age of 40-----------1:109 at the age of 45-----------1:32• Risk of recurrence is 1% ( 0.75% higher than

maternal age related risk• ** In case of parental aneuploidy---- 30% risk of

Trisomy in offspring

Methods available for screening for chromosomal abnormality

• Maternal age• Biochemical---1st trimester---PAPPA&β HCG,

• 2nd trimester---Triple & quadriple Test

• Ultrasound NT + Other markers

• Fetal DNA

Ultrasound screening for chromosomal abnormality

•Nuchal translucency(N.T)•Skin fold thickness behind the fetal cervical spine

• Timing: 11-13 +6days weeks of pregnancy

• 75-80% of trisomy 21

• 5-10% normal karyotype ( but could be associated with cardiac defects, diaphragmatic hernia, Exomphalos)

Nuchal translucency

Amniocentesis

Obtaining a sample of amniotic fluid surrounding the fetus during

pregnancy ”.

Indications: •Diagnostic (at 11- 20 weeks)

•Therapeutic( at any time)

Indications of amniocentesis:•Genetic amniocentesis:

Chromosomal analysis (Down syndrome)Chromosomal analysis (Down syndrome)

Spina bifida (Alpha fetoprotein)Spina bifida (Alpha fetoprotein)

Inherited diseases (muscular dystrophy)Inherited diseases (muscular dystrophy)

Bilirubin level in isoimmunizationBilirubin level in isoimmunization

Fetal lung maturation (L/S ratio)Fetal lung maturation (L/S ratio)

Theraputic amniocentesis:

•Reduce maternal stress in polyhydramnios

•Mainly in twin-twin transfusion or if abnormality associated

Amniocentesis

Chorionic villus sampling•Sampling is done to the cyto-trophoblastsSampling is done to the cyto-trophoblasts

done between 10-14 weeks of pregnancydone between 10-14 weeks of pregnancy

CVS

Thank you