1. Dr. Anjoo Agarwal Professor Dept of Obs & gyn KGMU, Lucknow
Fetal Monitoring
Dr. Anjoo Agarwal
Professor
Dept of Obs & gyn
KGMU, Lucknow

2. Objectives Understand aims of fetal monitoring
Understand methods of fetal monitoring
Understand limitations of fetal monitoring

3. Aims of Fetal Monitoring
Prevention of fetal death
Avoidance of unnecessary interventions
ACOG, AAP 2012

4. 23 yrs old woman G2P1+0 (1st FTND, A&H) presents at 38 wks pregnancy with C/o diminished fetal moments since 2 days.
Q. How significant do you think the problem is & what should be your next step?

5. Significance
Diminished fetal activity, may be a harbinger of impending fetal death
Sadovsky, 1973

6. Low Risk vs High Risk Any pregnancy may become high risk any time
C/o diminished fetal activity important in all cases

7. Role of Gestation ? Fetal activity starts at 7 wks
General body movements become organised wks
Fetal movement maturation continues till 36 wks
Criteria for interpretation of tests varies with gestation
Fetal viability an important consideration

8. Methods of Assessment Antepartum : DFMC NST CST Biophysical Profile
Doppler Velocimetry
Intrapartum:
External or Indirect
Internal or Direct
Fetal scalp blood sampling

9. DFMC
Cardiff “Count to 10”
One hour after each meal

10. NST FHR Acceleration in response to fetal movements
Test of fetal condition
Normal – reactive
Abnormal – non reactive

11. Reactive NST
≥ 32 weeks – 2 accelerations ≥ 15 bpm ≥ 15 sec during 20 min
< 32 wks – 2 accelerations ≥ 10 bpm ≥ 10 sec during 20 min

12. Fetal Heart Rate Acceleration

13. Electronic Fetal Monitoring
Pattern
Definition
Baseline
The mean FHR rounded to increments of 5 bpm during a 10 min segment, excluding
Periodic & episodic changes
Segment of baseline that differ by more than 25 bpm
The baseline must be for a minimum 2 min in any 10 min segment or the baseline for that time period is indeterminate. In this case, one may refer to the prior 10 min window to determine of baseline
Normal FHR baseline: 110 – 160 bpm
Tachycardia: FHR baseline > 160 bpm
Bradycardia: FHR baseline < 110 bpm
Fluctuations in the baseline FHR that are irregular in amplitude & frequency
Baseline Variability
Variability is visually quantified as the amplitude of peak-to-trough in bpm
Absent – amplitude range undetectable
Minimal – amplitude range detectable but ≤ 5 bpm or fewer
Moderate – amplitude range 6-25 bpm
Marked – amplitude range > 25 bpm
Acceleration
A visually apparent abrupt increase (onset to peak in < 30 sec) in the FHR
At 32 wks & beyond, an acceleration has a peak of 15 bpm or more have baseline, with a duration or more but less than 2 min from onset to return
Before 32 wks, an acceleration has a peak of 10 bpm or more above baseline, with a duration of ≥ 10 sec < 2 min from onset to return
Prolonged acceleration lasts ≥ 2 min but < 10 min
If an acceleration last 10 min, it is a baseline change
Visually apparent usually symmetrical gradual decrease & return of the FHR associated with a uterine contraction

15. No Variability

16. Minimal Variability

17. Moderate Variability

18. Increased Variability

19. Saltatory Pattern

20. CST/OCT
Tests uteroplacental function contraction stimulated by oxytocin infusion
Late decelerations indicate positive test

21. Biophysical Profile Nonstress test Fetal breathing Fetal movement
Fetal tone
Amniotic fluid volume

22. Modified Biophysical Profile
NST + AFI (cut off 5 cm)

23. Doppler Velocimetry
Umbilical artery
MCA
Ductus Venosus

24. Umbilical Artery Doppler
Abnormal if –
S/D > 95% percentile for GA
Absent end diastolic flow – 10% PM
Reversed end diastolic flow – 33% PM
Utility only in FGR

25. MCA Fetal Hypoxia → brain sparing → ↑ Cerebro vascular resistance (RI)
Also useful in fetal anaemia where ↑ PSV

26. Ductus Venosus Good correlation with perinatal outcome
But by the time affected it is too late
Still in experimental stage

27. Final Recommendations
Start at weeks in HR cases
Severe complications may require testing at weeks
Repeat weekly/ every 7 days
Most commonly used – modified biophysical profile

28. MCQ
NST is used to test 1 uteroplacental bloodflow 2 fetal condition 3 response to uterine contractions 4 fetal anaemia

29. MCQ
A 35 yr old G1 P0+0 presents at 34 wks with GDM. It is recommended that she be monitored by 1 weekly NST 2 DFMC 3 Daily doppler 4 all of the above

30. MCQ
The acceleration of FHR in NST should be of 1 at least 20 min duration 2 at least 20 sec duration 3 at least 15 sec duration 4 at least 15 min duration