BASED ON MUNROE KERR'S

1. INTRAPARTUM FETAL
SURVEILLANCE
Dr K.G.Hewawitharana
Registrar-DMH

2. What does it mean?
• It is the “ assessment of fetal wellbeing from
passage of intrauterine life to extra uterine
life”
(www.glowm.com)

3. Why it is important???
• The greatest challenge of obstetrician is to
ensure wellness of mother and growing fetus
(during parturition fetus is at very stressful
condition that it should bear)
• Greatest enemy is ACUTE HYPOXIA of fetus
that can happen in delivery. This brings
serious neurological problems or even
stillbirths.

4. What brings Acute Hypoxia?
• Uterine hyper stimulation
• Placental Abruptions
• Umbilical cord accidents
• We clinicians should be able to recognize
these events to intervene.

5. Current methods available
• Intermittent Intelligent Auscultation
• Electronic Fetal Monitoring
• Fetal Scalp Blood Sampling
• Fetal Scalp Lactate Test
• Fetal Stimulation Test
• Fetal Pulse Oxymetry
• Fetal ECG
• Clinical Assessments

6. Intermittent Auscultation
( Pinard or hand held Doppler)
• Alone enough for low risk pregnancies
@ First stage
Auscultate for 1 min soon after contractions in each 15 min gap
@ Second stage
Monitor FHS in each 5 min interval

7. What indicates by “intelligent”
• Feel for fetal movements and listen FHS >
15bpm increment during this(acceleration)
• After contraction, look for any reduction of
FHS(deceleration)
• If movement associated FHS rise noted , CTG
also likely to be reactive.

8. ELECTRONIC FETAL MONITERING
• AKA Cardiotocography (CTG)
• 2 types as External and Internal CTG
• Advised to do as continuous monitoring if
pregnancy is a high risk
Maternal causes
GDM,PIH,VBAC,APH,PROM>24hrs or INDUSED
Fetal Causes
FGR,LOW AFI,TWINS,BREECH,MECONIUM

9. Fetal Scalp Blood Sampling
• This should not be the choice if preterminal
CTG patterns or clinical situations happening
Eg ; Prolonged Bradycardia , markedly reduced
variability ,Late/Atypical Deceleration , cord
accidents.
THIS IS CONTRAINDICATED when known BLEEDING DIASTHESIS
or TRANSMISSIBLE INFECTIONS present

10. FBS Cont.
• This might not reflect hypoxia or acidosis in
some situations.
• If pH value
< 7.2 ; immediate delivery
7.2-7.25 ; repeat again in ½ hr
>7.25 ; observe for CTG improvement and repeat if necessary
GOOD Clinical assessment & CTG reduces need of SCALP
SAMPLING

11. Fetal stimulation tests
• FHR acceleration in response to external
stimulation is likely that fetus is not Acidotic
• Scalp simulation with ALLIS TISSUE FORCEP or
VIBROACOUSTIC STIMULATION across
maternal abdomen is used.
• If no response there is nearly 50% chance of
fetal acidosis

12. Fetal Pulse Oxymetry
• spO2 fluctuate in fetus at 30%- 80%
• If it is less than 30% for 10min or more,
imminent delivery plan is required.
• This is also an application of scalp electrode
and interpretation as electronic machine
reading

13. Fetal Scalp Lactate Sampling
• Metabolic acidosis is reflected by pH , BE and
lactate level
• If hypoxia for more than 10 min , lactate
begins to buildup in fetal blood. Longer the
duration , accumulation also more. But it’s
disappearance is more time consuming.
• Scalp lactate levels correlate with umbilical
cord blood lactate Levels.

14. LACTATE CONT.
• Why lactate is more effective detection
method when compare with FBS
BECAUSE IT NEEDS ONLY 1/7 VOLUME OF
SAMPLE NEED FOR FBS(5microL Vs 35 micro)

15. HOW TO INTERPRINT
• < 4.2 ; Normal. If CTG changes still present
consider to repeat in 1 hr
• 4.2-4.8 ; Pre acidemia. Repeat in 30 min or
deliver if significant rise from last value
• >4.8 ; Acidemia. Immediate delivery is need.

16. Fetal ECG Analysis
• We all know about ECG . It is…….
• ST segment/ T wave elevation favors hypoxic
event in the myocardium , adrenalin surges
• Such myocardial ischemic changes is related to
cardiac glycogen content
• Scalp electrode is used together with maternal
skin electrode and analyze using ST wave
analyzer

17. ECG CONT.
• This produce sample ECG from 30 received
complexes & analyze T/QRS ratio and changes
of ST segment called BIPHASIC ST wave form
Rise of T/QRS ratio
Increasing ST Waveform grading
Suggestive of cardiac ischemia of fetus

18. How To Get T/QRS Ratio
• Computer calculate lowest ratio for 20 min
• Then this last ratio is validated for next 3 hrs
ahead to see any rise of ratio
• Even if we stop the STAN analyzer, and
reconnect within next 3 hrs ,still first base line
ratio is valid

19. What is this Biphasic ST waveform
• If the ST wave is above the isoelectric line,
then it is called BST 1
• If it cuts the line, then its called BST 11
• If changes are below isoelectric line,BST111

20. • This change is due to ventricular
repolarization and current flow from
endocardium to epicardium.
• Preterm fetuses show these changes . Hence
fetal ECG is not applicable to preterm
fetuses(<36 weeks)

21. STAN EVENT
• Prolong Biphasic events are known as STAN
event . They are noted as >2 or >5 min events
• > 2 STAN events + suspicious CTG
OR
>1 STAN event + pathological CTG indicate to
intervene
• But its not the LSCS always . Even we may
resuscitate with CTG monitoring
• If CTG is difficult to describe , try FBS too.

23. • Fetal ECG + CTG co use have reduced the
need of FBS , Fetal acidosis and operative
delivery rates.(Acta Obstet gynecol Scand
2014;571-586)

24. CLINICAL ASSESMENT
Palpate for prolong contractions
Uterine tenderness/Scar tenderness
Fresh PV bleeding
MECONIUM
can be used to recognize ongoing fetal adverse
events and should correlate with other
detection methods

25. MECONIUM
• Appears usually at term . but rare in preterm
unless Listeriosis like infection or hypoxic event.
• At term this indicates functional maturity and as
with dates reach post term , incident is 5% vs
15%.
• But PG induction is another reason as PG
increases gut motility.
• Alternative explanation is anal sphincter
relaxation at hypoxia cause meconium passage

26. • Its not common to find meconium in acute
hypoxia like cord prolapse or abruptions.
• Meconium does not always sense that fetus in
trouble . And clear liquor is not promising for
well oxygenated fetus . so use this finding
wisely without getting ourselves into trouble.
• Thick meconium with lack of free flow is
indicative of poor renal perfusion . Now fetal
brain is so stressed to get more blood . so
chance of fetal acidemia is higher than thin
meconium stain with free flow of liquor.
• But remember if CTG is pathological even with
thin meconium , chance to get acidosis rises
sharply than pathological CTG alone

27. • Because of this reason , if meconium present
better to do CTG monitering And consider
early scalp blood sampling.
• Meconium aspiration has no correlation to
fetal acidosis.

28. Intrapartum maternal pyrexia
• > 38 *c is known to be associated with
increased incidents of fetal encephalopathy.
(Odds ratio is 9.5 ) AND acidosis risk is
markedly rise . Hence fluid therapy and
paracetamol is useful interventions.(best
practice in labour,2nd edition)

29. BEFOR I STOP THIS
• EXPECTED RESULTS OF IP SURVEILLANCE
METHODS ARE LESS THAN OPTIMAL.
• Reasons include poor communication , poor
CTG Interpritation , Inabilty to put clinicals
together with high tech findings to make
decisions,delay in taking actions,poor team
work(4th annual report of CESDI-1997)

30. LETS TOGETRHER TRY
• Intermittent Intelligent Auscultation
• Electronic Fetal Monitoring
• Fetal Scalp Blood Sampling
• Fetal Scalp Lactate Test
• Fetal Stimulation Test
• Fetal Pulse Oxymetry
• Fetal ECG
• Clinical Assessments

31. REFERENCES
• 12th Edition Munroe Kerr’s
• 02nd Edition Best Practice In Labour &Delivery
• 2014 Nice Guideline Of Intrapartum Fetal
Surveillance
• Internet based literatures

32. THANK YOU