Foetal Monitoring

Obstetric And Gynaecology

Principles of fetal monitoring



PRINCIPLES OF FETAL MONITORINGMohd Hanafi Ramlee





I’M SORRY, I CAN’T INTERPRET SOME OF THE PICTURE HERE!!!

BUT I’LL TRY MY BEST!!!



AIMS OF FETAL MONITORING

• Assessment of fetal well-being especially in high-risk mother

• Assessments of fetal growth• Identification of fetal abnormalities and

condition in all stages of pregnancy• Determination of gestational period• To ensure a safe delivery



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan

4. Amniotic Fluid Index

5. Doppler Investigation

6. Cardio –toco -graph

7. Meconium Stained Liqour



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index

5. Doppler Investigati

on





1. Clinical

Sign

Weight Gain

Symphysio –

fundal Height

WEIGHT GAIN

• Cheap and simple method using weighing machine

• Mother should gain 0.5 kg/week during 2nd and early 3rd trimester then, the rate of weight gain is plateaus off

• ↓: possibilities of IUGR, persistent nausea and vomiting or forced dieting

• ↑: PIH, renal disease and polyhydramnios.



1. Clinical

Sign

Weight Gain

Symphysio –

fundal Height

SYMPHYSIOFUNDAL HEIGHT

• At least 2 times weekly• The centimeters should roughly

correspond to the period of gestation

• ↑: polyhydramnios• ↓: oligohydramnios



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





FETAL KICK CHART• Commonest methods – Cardiff ‘count to ten’• Start count at 9am every morning• Record the time taken for baby to move 10 times • Normal fetal activity-little variation in time taken• ↓ fetal activity [fetal compromise] - delay in time taken• Benefit: detection of fetal compromise, more easier and

cheap• Limitation: Maternal anxiety is common, unsure of

movement, is a crude guide and sometimes inconsistent



A FAVOURABLE FETAL MOVEMENT CHART

Day

Time (am/pm))

Patient’s Name



AN UNFAVOURABLE FETAL MOVEMENT CHART

Day

Time (am/pm))

Patient’s Name



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





Ultrasound

Diagnostic

Doppler

Routine

MRIUltraso

und

Diagnostic

Doppler

Routine

MRI



DIAGNOSTIC ULTRASOUND SCAN- 2 dimensional map of content of uterus.- Image constantly updated in real time

and fetal cardiac and other movement can be studied.

- < 12 weeks usage of transvaginal transducer.

- > 12 weeks usage of abdominal transducer.

- Good image depend on operator skill.- Disadvantages : Bio effects on cells,

inducing heating.



transvaginal -TRANDUCER - abdominal



Diagnostic Ultrasound

Pregnancy

FetalPlacenta

Others

Early Problems

Age Assessment

Symmetry

Measurement

Weight

Growth

Anatomy

Morphology

Location

Umbilical Cord Abnormalities

Amniotic Fluid Volume

Invasive Procedure



EARLY PREGNANCY PROBLEMS

- transvaginal ultrasound role in diagnosis of disorder in early pregnancy.

• E.g. miscarriage - fetus present, absent fetal heart• E.g. ectopic pregnancy- absent of gestational sac within uterus



FETAL MEASUREMENTS

SERIAL ULTRASOUND MEASUREMENT OF THE FETUS (>24/52 POG)

Common [2wk interval]

Biparietal Diameter & Head Circumference Femur Length

Sensitive

Abdominal Circumference

SERIAL ULTRASOUND MEASUREMENT OF THE FETUS (<24/52 POG)

Crown-rump Length



FETAL MEASUREMENT

• Common = relatively ‘spared’ in growth restriction

• Sensitive = organ that are sensitive to changes to any factor that cause IUGR [liver/spleen]



CROWN-RUMP LENGTH



CROWN-RUMP LENGTH

Geatational sac

Yolk sac

Fetal pole



BPD, HC LENGTH

Biparietal diameter

Head circumference



BPD, HC LENGTH



FEMUR LENGTH

Femur length



FEMUR LENGTH



ABDOMINAL CIRCUMFERENCE

Abdominal Circumference



GESTATIONAL AGE ASSESSMENT

• CRL/BPD these measurements are plotted on the normogram

• Predictions of gestational age by ultrasound scan before 20 weeks is more accurate than predictions from last menstrual period.

• Measurements are done at least 2 week apart• Measurements are plotted in centile-charts

against a normogram



MEASUREMENT ON FETAL GROWTH CHART



Consistent growth of Small fetus



Slowed growth—fetal compromise



FETAL SYMMETRY

• ↑HC: Hydrocephalus• ↓HC: Microcephaly• ↓FL: constitutional short stature,

achondroplasia• ↑AC: Diabetic pregnancy,• ↓AC: triploidy / trisomy 18• Asymmetry: IUGR



PLACENTA

• Transvaginal scan: if the placenta covers the internal os major placenta praevia

• Mid pregnancy scan low-lying placenta• 3rd pregnancy scan minor placenta praevia



OTHERS CONDITION

• Amniotic Fluid scan: commonly base on AFI [if <2cm: Oligohydramnious, >7cm: Polyhdramnious]

• Umbilical Cord: scan with colour doppler [Nuchal displacement: common event associated with fetal distress]

• Invasive procedure: amniocentesis, chorion villus sampling, cordocentesis, fetal bladder shunt therapy, fetoscopy and endoscope.



Ultrasound

Diagnostic

Doppler

Routine

MRIUltraso

und

Diagnostic

Doppler

Routine

MRI



AIMS OF ROUTINE ULTRASOUND SCAN

Early scan(11-14 weeks)•To confirm fetal viability•EDD•Diagnose multiple gestation•Identify gross abnormalities

Mid-pregnancy scan(18-22 weeks)

•EDD, if not done.•Detailed fetal anatomical survey•Placenta location•AFI

Third-pregnancy scan(>22 weeks)

•Fetal growth•Fetal well being



Ultrasound

Diagnostic

Doppler

Routine

MRI

• Magnetic Resonance Imaging: useful when i) US images are not diagnostic or ii) suboptimal because of maternal obesity



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





MRI



39

AMNIOTIC FLUID Produce : Kidneys & Lungs Remove : Fetal swallowing and blood

Functions : Prevent mechanical injury, permit movement and lung development

4 quadrant method (R/L hypocondrium R/L illiac fossa)



AMNIOTIC FLUID INDEX• Liquor volume reflects the placental size, placental

function and fetal metabolism• Sum of all the maximum vertical pool of liquor from

the 4 quadrant of the uterus• In 3rd tri, normal AFI should be between 10 and 25cm • AFI -below 5cm -oligohydramnios

above 25cm -polyhydramnios



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





DOPPLER ULTRASOUND

Measuring blood velocity in umbilical artery of fetus.

Recorded in waveform pattern :Systolic - blood velocity speeds up.Diastolic - blood velocity slows down (depending

amount resistant in arterial bed in placenta).



Doppler Umbilical Artery Waveforms• Measure blood velocity in umbilical artery of fetus• Recorded in waveform pattern showing a systolic &

diastolic component• During normal fetal life, diastolic flow in the umbilical

artery↑ gradually (placental resistance falls) with gestation

• In placental damage/insufficiency- absent/reversed end diastolic flow which leads to fetal distress and intrauterine death.



Doppler Uterine Artery Waveforms

• Assessment of uterine artery waveforms at 24th weeks’ gestation.

• Benefits: Even at absence of risk factors, severely abnormal waveforms identify 75% of pregnancies at risk of adverse neonatal outcome in early 3rd trimester.

• Limitations: Less effective at prediction of later problems.



Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





Principles of Fetal Monitoring

49

Cardiotocograph (CTG)

Computerized tracing of fetal heart rate pattern

Sensitive Reflects physiological

and pathological changes




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CTG Parameters:

Baseline heart rate :Normally 110 – 160bpm<110 bpm = bradycardia >160 bpm = tachycardia




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Baseline variability : Reflects normal fetal autonomic nervous system. Modified by :

Fetal sleep states and activity.Hypoxia.Fetal infection.Drugs e.g. opioids and hypnotics (reduce

baseline variability). Baseline variability – 8 bpm and 2-6 times in a minute.




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Fetal heart rate (FHR) acceleration.

Increased baseline FHR at least 15 bpm lasting at least 15 seconds.

Within 20 – 30 minutes CTG, 2 or more accelerations present define as reactive trace.

Importance – fetal hypoxia




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FHR deceleration Transient reduction fetal heart rate of 15 bpm or > lasting more than

15 seconds.

Type 1 decelerationnadir (lowest point) of deceleration coincides with the peak of uterine contraction

Type 2 decelerationnadir of deceleration lags behind and persist even after the peak of uterine contraction

Variable deceleration patternnadir variable in depth and timing peak of contraction




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Methods

1. Clinical Sign

2. Fetal Kick Chart

3. Ultrasound

Scan4. Amniotic

Fluid Index


on





Meconium Stained Liquor

• Sign of fetal compromise• Can only be diagnose during labour, or only after

the membrane have been ruptured• May be due to– Intestinal hurry– Spontaneous dilatation of anal sphincters

• Manifestations of foetal hypoxia.





OTHERS MONITORINGMohd Hanafi Ramlee



Principles of Fetal Monitoring 61

Biochemical ScreeningPrenatal screening test: Fetal nuchal - measurement of fluid filled

translucency space on post. surface of fetal neck.- increase measurement

associated with fetuses with major chromosomal abnormalities and sex chromosomal abnormalities (e.g. Down syndrome).

Maternal serum screening - neural tube defect and Down syndrome.




Fetal Nuchal Translucency




Maternal full blood indices/electrophoresis – detect thalasemia.

Sickledex test – sickle cell disease.Maternal blood group/rhesus

antibodies.Maternal serum virology –

CMV/toxoplasmosis/Rubella/parvovirus

Serology for syphilis.




Maternal Serum Screening15 – 20 weeks of gestation.maternal serum alpha-fetoprotein (AFP)

screening for neural tube defects (NTDs) and Down syndrome.

Increase level - fetal open NTDs.Decrease level - Down syndrome.

Screening test on Down syndrome:maternal serum AFP.human beta-chorionic gonadotropinunconjugated oestriol.advanced age – risk.



Biophysical ProfileBiophysical variable Normal (score 2) Abnormal (score 0)

Fetal breathing movements

> 1 episode for 30s in 30 min

Absent < 30s in 30 min

Gross body movements > 3 body/ limb movements in 30min

< 3 body/ limb movements in 30min

Fetal tone > 1 episode body/ limb extension followed by return to flexion, open-close cycle of fetal hand

Slow, or absent extension-flexion of or body or limbs

Reactive fetal heart rate >2 accelerations with fetal movements in 30min

<2 accelerations, or 1+deceleration in 30min

Qualities amniotic fluid >1 pool of fluid, at least 1cm x 1cm

Either no measurable pool, or pool <1cm x 1cm





THANK YOU FOR YOUR ATTENTION

Foetal Monitoring

Health & Medicine

Transcript of Foetal Monitoring