This document discusses evidence-based approaches to antenatal Doppler fetal surveillance. It begins by outlining the objectives and aims of fetal surveillance, including identifying fetuses at risk of hypoxia and improving perinatal outcomes. It then describes various methods of fetal surveillance, including daily fetal movement counts, non-stress tests, biophysical profiles, and Doppler velocimetry. The document discusses the indications and measurements of Doppler indices for the uterine, umbilical, and middle cerebral arteries. It reviews recent evidence showing that Doppler ultrasound in high-risk pregnancies can reduce perinatal deaths and interventions without increasing them in low-risk pregnancies. The document concludes by emphasizing that not all pregnancies require surveillance and that monitoring

1. Evidence Based Approach To
Antenatal Doppler Fetal
Surveillance
DR PRAMAN KUSHWAH
DrNB NEONATOLOGY RESIDENT
NICE HOSPITAL, HYDERABAD

2. Objectives
1. Aim of fetal surveliiance
2. Methods of fetal survelliance
3. Indication for fetal survelliance
4. Fetal Doppler in fetal survelliance – Indices and
Measurements
5. Uterine, Umbilical and Middle cerebral artery Doppler
6. Recent Evidences

3. Aim Of Fetal Surveillance
• Identifying fetus at greater risk of hypoxia
• Minimizing the morbidity by optimizing the timing of delivery
• Improving perinatal outcomes by decreasing stillbirths and perinatal asphyxia
• Improve long term neurologic outcomes by timely intervention
• Relies on fetal biophysical parameters (eg. heart rate and movement) that are
sensitive to hypoxemia and acidemia
• FIGO recommends to begin at 24-28 weeks in high risk patients.

4.  Daily Fetal Movement Count
 Non Stress Test
 Contraction stress test
 Manning score or biophysical profile
 Doppler Velocimetry
Methods Of Fetal Surveillance
Cardiff Method : Count of 10 fetal movements in 12 hours
Designed to evaluate FHR response to maternal uterine contractions
Describes fetal heart rate acceleration to fetal movement as a sign of fetal health

5. Biophysical Profile
Non Stress Test
• At least one episode continuing for more than 30
seconds
Fetal Breathing
movements
• At least 3 limb or body movements
Gross Body Movements
• An episode of active extension with return to flexion
of a limb or trunk OR opening or closing of the hand
Fetal Muscle Tone
• At least one cord and limb-free fluid pocket which is
2 cm by 2 cm in two measurements at right angles.
Amniotic fluid volume
Manning et al, 1980

6. Fanaroff and Martin’s Neonatal-Perinatal Medicine, Diseases of the fetus and infant, 10th edition

7. Fetal Doppler In Antenatal Surveillance
•For evaluation of high-risk pregnancies especially, FGR is suspected with EFW <
10th centile.
•Doppler sonography has both diagnostic and predictive value in fetus with
potential FGR.
•Doppler USG of fetal vessels can identify the SGA from true FGR fetus, thus
avoiding iatrogenic prematurity and additional antenatal testing.

8. Objective : To assess the effects on obstetric practice and pregnancy outcome of routine fetal
and umbilical Doppler ultrasound in unselected and low-risk pregnancies.
Population : Included five trials that recruited 14,624 women, with data analysed for 14,185
women.
Result : No group differences noted for the review’s primary outcomes of perinatal death and
neonatal morbidity. Routine fetal and umbilical Doppler ultrasound examination in low-risk or
unselected populations did not result in increased antenatal, obstetric and neonatal
interventions.
Cochrane Database of Systematic Reviews 2015, Issue 4. Art. No.: CD001450.

9. • Objective: To assess the effects of Doppler ultrasound used in high-risk pregnancies on
obstetric care and fetal outcomes
• Selection criteria: Nineteen trials involving 10,667 women were included (high risk
pregnancies) were included, compared the use of Doppler ultrasound of the umbilical
artery of the unborn baby with no Doppler or with cardiotocography (CTG).
• Results: The use of Doppler ultrasound in high-risk pregnancy was associated with a
reduction in perinatal deaths (29%) with fewer inductions of labour and fewer caesarean
sections. No difference was found in operative vaginal births nor in Apgar scores less than
seven at five minutes
Cochrane Database of Systematic Reviews 2017, Issue 6. Art. No.: CD007529.

10. Pathophysiological Basis Of Antenatal Doppler
Doppler Velocimetry for Fetal Surveillance: Adverse Perinatal Outcome and Fetal Hypoxia. Dev Maulik, Reinaldo Figueroa. 2006
Fetus responds to chronic hypoxemia with a detectable sequence of
biophysical changes
Physiological adaptation → physiological decompensation
DU may not identify fetuses at risk of death from an acute hypoxemic
insult, such as a complete placental abruption.

11. Stress
Chronic respiratory and nutritive insufficiency
Primary adaptive response
Decreased fetal growth rate
Secondary adaptive response
Fetal energy conservation – decr. HR reactivity, fetal movement
Circulatory redistribution – doppler changes
Fetal growth preferred over placental growth
Increased efficiency of placental exchange
Polycythemia
Fetal Response To Chronic Intrauterine Hypoxia

12. Stress
Chronic respiratory and nutritive insufficiency
Primary adaptive response
Decreased fetal growth rate
Secondary adaptive response
Fetal energy conservation – dec HR reactivity, fetal movement
Circulatory redistribution – doppler changes
Fetal growth preferred over placental growth
Increased efficiency of placental exchange
Polycythemia
Progressive decompensation
Hypoxia  respiratory acidosis  metabolic acidosis
High impedance in fetoplacental and systemic circulation– AEDF in UA
Declining AFI  Oligohydramnios
Loss of fetal movement, HR variability
Persistent late de-accelerations
Death
Doppler Velocimetry for Fetal Surveillance: Adverse Perinatal Outcome and Fetal Hypoxia. Dev Maulik, Reinaldo Figueroa. 2006

13. Doppler USG - History
• DU was successfully introduced in OBG in 1977.
• Fitzgerald et al. were the first to report noninvasive demonstration of the umbilical
cord (UC) blood flow pattern and suggested that the umbilical artery (UA) waveforms
could be abnormal in fetuses with intrauterine growth-restriction (IUGR).

14. Doppler Velocimetry - Uses
• Non-invasive measurement of blood flow in maternal and fetal blood vessels
• Assesses uteroplacental blood flow and fetal physiological responses.
• DU waveforms- not only reflect blood velocity but also presence and direction of
flow, velocity profile, flow volume, and impedance.

15. Doppler Indices
• Angle-independent, doppler indices mentioned below were developed for flow
velocimetry to avoid inter- and intra-observer variation

16. Doppler Indices
Doppler Imaging Ultrasonography in Assessment of Fetal Well-being NeoReviews Vol.5 No.6 June 2004

17. Doppler Assessment
• UTERINE ARTERY
• UMBILICAL ARTERY
• MIDDLE CEREBRAL ARTERY
• VENOUS (UV,DV,IVC)

18. Uterine Artery Doppler
• Uterine artery re-modelling is the hallmark of successful placentation.
• In normal pregnancy, placental trophoblast cells invade the inner third of the
myometrium  optimizing delivery of oxygen and nutrients to the fetus.
• Significant increase in uterine artery compliance  increased flow in diastole.
• In preeclampsia  failure of trophoblast invasion of the uterine muscular wall 
spiral arteries retain the muscle elastic coating  impedance to blood flow persists.
• PI > 95th or persistent diastolic notch done in 2nd trimester predict pre-eclampsia
and IUGR
Uterine artery Doppler flow studies in obstetric practice Journal of Prenatal Medicine 2010; 4 (4): 59-62

19. Normal uterine artery at 12 weeks shows
relatively high resistance, absent notching
Normal mid-trimester uterine artery, increased
diastolic flow
Normal third trimester uterine artery, very low
resistance
High resistance with persistent notching may be
normal in first trimester, not in this 24-week
gestation USG
Very high resistance, marked notching, absent
diastolic velocities in a woman with lupus,
proteinuric pre-eclampsia, and severe IUGR at
28 weeks

20. Umbilical Artery Doppler
• Umbilical artery (UA)- most easily measured parameter
• Measure of fetal systemic and placental vascular impedance.
• Placentas with abnormal UA doppler have slender capillaries with decreased
capillary loops in gas-exchanging terminal villi.
• Maternal or placental conditions that obliterate small muscular arteries in the
placental tertiary stem villi result in a progressive decrease in end-diastolic flow in
the umbilical artery Doppler waveform until absent.
• REDF has been shown to be associated with obliteration of >70% of placental
tertiary villi.
Doppler Imaging Ultrasonography in Assessment of Fetal Well-being NeoReviews Vol.5 No.6 June 2004
Antenatal tests of fetal wellbeing. Seminars in Fetal & Neonatal Medicine 20 (2015) 138e143

21. Umbilical Artery Doppler
Normal umbilical artery at 18 weeks shows
relatively high resistance, but consistent diastolic
flow
Normal umbilical artery at 36 weeks, low
resistance, generous diastolic flow
High resistance, diastolic velocity low
Absent end-diastolic velocity (AEDV)
Reversed diastolic velocity (REDV) in severe
intrauterine growth restriction (IUGR)

22. Abnormal UA Doppler
1. Prediction of fetal hypoxia and acidosis especially if AEDF
2. A/REDF  higher adverse perinatal outcomes, increased perinatal mortality upto
28% and increased requirement of intensive care.
3. Higher prevalence of doppler abnormalities seen in chromosomal disorders
(especially trisomy 13, 18, and 21) and congenital anomalies.
4. Many studies have shown that abnormal doppler findings esp A/REDF are
associated with long term neurodevelopmental impairment.
Baschat AA, Viscardi RM, Hussey-Gardner B, et al. Infant neurodevelopment following fetal growth restriction: relationship with
antepartum surveillance parameters. Ultrasound Obstet Gynecol 2009;33:44–50.

23. MCA Doppler
1) To detect evidence of redistribution of fetal
blood flow to the brain in cases of placental
insufficiency, fetal hypoxia, and associated
fetal growth restriction
2) To detect increased blood flow to the brain in
cases of fetal anemia.

24. MCA Doppler And IUGR
• MCA resistance is normally high throughout gestation.
• Increased MCA diastolic velocity in FGR i.e. ‘brain-sparing’ effect  secondary to
hypoxia- induced cerebrovascular dilation
• Represents a deterioration in placental respiratory function  decrease in PI.
• These compensatory changes are sequential
• Depend on the maintenance of adequate cardiac output.
• When IUGR becomes terminal, falling cardiac function may result in the regression
of MCA flow, so- called ‘pseudo - normalization’

25. Normal middle cerebral artery (MCA) at term –
normal peak systolic velocity (58 cm/s), high
resistance, low end-diastolic velocity.
‘Brain sparing’ MCA – lower peak, much higher
diastolic velocity suggests cerebro-vasodilation
Anemic fetus with retained high resistance,
elevated peak systolic velocity (77 cm/s).

26. Cerebroplacental Ratio
• The CPR is calculated as the ratio of doppler index (pulsatility index (PI), resistance
index (RI), or systolic/diastolic ratio (S/D)) of the MCA by that of the UA. Most
commonly PI is used.
• High UA PI values and low MCA PI values are associated with adverse outcomes.
• Low CPR (<1)  risk of adverse perinatal outcome.
Cerebro-placental Ratio = Middle Cerebral Artery PI
Umbilical Artery PI
Predictive accuracy of cerebroplacental ratio for adverse perinatal and neurodevelopmental outcomes in suspected fetal growth restriction:
systematic review and meta-analysis. Ultrasound Obstet Gynecol 2018; 52: 430–441.

27. MCA Doppler And Fetal Anemia
• MCA PSV (Peak Systolic Velocity)  risk of Rh disease or anemia due to parvovirus
B19.
• Raised PSV but antibody is negative  acute or chronic feto-maternal haemorrhage
• For Rh sensitization – done as early as 16-18 weeks, repeated 1-2 weeks interval
• The sensitivity of increased MCA PSV for the prediction of mod-severe anemia was
100% either in the presence or absence of hydrops, with a false positive rate of 12%.

28. Fetal Anemia
Fetal anemia progresses (decreased viscosity)
Right and left ventricular output increases by 45%, heart rate unchanged
Fetal blood vessel cross sectional area unchanged
Poiseuille’s law (velocity directly proportional to flow) (flow=velocity X cross
sectional area)
Increased flow
Normal Fetal anemia

30. GRIT (Growth Restriction Intervention Trial)
• Population: 69 hospitals in 13 European countries, 1997-2003. 587 babies, 24-36 weeks
gestation with IUGR and abnormal doppler.
• Aim: Aim was to compare the effect of delivering early to avoid intrauterine hypoxia, to
delaying delivery for as long as possible, in order to gain maturity
• Result: Median time-to-delivery interval - 0.9 days in immediate group and 4.9 days in
delay group. Total deaths prior to discharge were 29 (10%) in the immediate group versus
27 (9%) in the delay group.

31. Lancet 2004; 364: 513–2
Conclusion : At 2 years of age, there is a trend towards more disability in the immediate delivery group,
but no overall difference in Griffiths DQ.

32. TRUFFLE trial
• (P) Trial of Umbilical and Fetal Flow in Europe 20 European perinatal centers, 2005 – 2010.
Women with a singleton fetus, 26–32 weeks, AC < 10th percentile and UA PI >95th percentile
• (I) AIM: To assess whether changes in the fetal ductus venosus Doppler waveform (DV)
could be used as indications for delivery instead of cardiotocography short-term variation
(STV)
• 3 armed RCT:
Group 1: control - current standard of care: timing of delivery based on CTG low STV(red HR)
Group 2a: Early ductus venosus changes (PI > 95th centile)
Group 2b: Late ductus venosus changes (absent a-wave)
Lancet 2015; 385: 2162–72

33. TRUFFLE trial
• (O) Primary outcome: Survival without cerebral palsy or neurosensory impairment, or a
Bayley III developmental score of less than 85, at 2 years of age
• Result :The proportion of infants surviving without neuro-impairment did not differ
between the CTG STV (111 [77%] of 144 infants with known outcome), DV p95 (119 [84%] of
142), and DV no A (133 [85%] of 157) groups (ptrend=0·09)
Concluded : The proportion of infants who survived without neurodevelopmental impairment between the
three groups did not differ; neurodevelopmental impairment was least frequent in survivors randomly
assigned to the DV no A group compared with those in the CTG STV group (p trend across the three groups of
0·004). Their findings support waiting for late ductus venosus changes before delivery because no increase in
hypoxia mediated deaths occurred and neuro-impairment is less frequent than when delivery is based on
computerised CTG changes.

35. Take home message
• All Pregnancies do not require Antepartum fetal surveillance with doppler
• High risk pregnancies should be identified timely and appropriate fetal monitoring should be
initiated
• Early and late onset FGR have different pathophysiology and different findings on fetal surveillance
• Umbilical Artery dopplers have limited role in late onset FGR.
• Monitoring should be based on integration of Doppler, BPP, NST rather than one test alone.
• Timing of delivery should be individualized for each patient.

36. Thank You