Why umblical artery
doppler
 Venous doppler DV and umbilical vein
 Arterial doppler umbilical

aorta

middlde cereberal artery
How assess the umbilical artery
doppler
 Location where the cord is sampled — The indices are
higher at the fetal than at the placental end of the cord [11].
For PW Doppler, a mid-level free floating loop of the cord
should be used for sampling when the site of Doppler
sampling can be selected. Others recommend using the fetal
end of the umbilical cord [13]. The clinical significance of
these variations in measurement technique remains unclear
Management of increased
PI in umbilical artey
 When defined by customised fetal weight standards 81% of
SGA fetuses have a normal umbilical
 artery Doppler.141 Outpatient management is safe in this
group142 and it may be reasonable to repeat
 Doppler surveillance every 14 days; one small randomised
trial involving 167 SGA fetuses with
 normal umbilical artery Doppler investigated frequency of
surveillance; twice–weekly compared to
 two weekly monitoring resulted in earlier deliveries and more
inductions of labour with no difference in neonatal morbidity.
 When umbilical artery Doppler flow indices are abnormal
(pulsatility or resistance index > +2 SDs above
 mean for gestational age) and delivery is not indicated
repeat surveillance twice weekly in fetuses with
 end–diastolic velocities present and daily in fetuses with
absent/reversed end–diastolic frequencies.
 In SGA fetuses with abnormal umbilical artery Doppler where
there is not an indication for delivery
 the optimal frequency of surveillance is unclear. Until
definitive evidence becomes available it is
 reasonable to repeat surveillance twice weekly in fetuses
with end–diastolic velocities present and
 daily in fetuses with absent or reversed end–diastolic
velocities (AREDV).
Up to date

Increased pI 0r AEDV
After
or 34
deliver
before
34
Daily
doppler
and nst
BPP
Before 34
 Revesed UA flow or non reassuring BBP
deliver
High pi and after 34
 A high or increasing DI in the presence of end-diastolic flow
warrants more intensive fetal surveillance, such as weekly
umbilical Doppler ultrasound and once or twice per week
NST, BPP, or modified BPP, as dictated by the clinical
condition. If fetal surveillance tests indicate fetal compromise
(eg, nonreactive NST, poor fetal heart rate baseline
variability, persistent late decelerations, oligohydramnios, or
BPP score <4), delivery should be strongly considered, with
the mode of delivery determined by obstetrical factors (eg,
gestational age, presentation, fetal heart rate tracing) and
maternal factors (eg, medical complications, cervical status).
 Individualized
management
 Application of the BPP to the growth restricted fetus remote
from term may be less reliable since the preterm fetus may
not have achieved maturity of the biophysiologic processes
measured by this test. Furthermore, although many large
observational studies have demonstrated the usefulness of
the BPP in antepartum fetal assessment, there is a paucity of
evidence derived from randomized trials
Frequency of fetal surveillance
 Weekly Doppler should be complemented by twice weekly
BPP or another combination of two antenatal tests (nonstress
test and modified BPP or BPP) when FGR is complicated by
oligohydramnios, preeclampsia, deceleration of fetal growth,
increasing umbilical Dopper index, or other complications,
even when umbilical artery end diastolic flow is present.
c
 In the term SGA fetus with normal umbilical artery
Doppler, an abnormal middle cerebral artery Doppler
 (PI < 5th centile) has moderate predictive value for
acidosis at birth and should be used to time delivery.
 Cerebral vasodilatation is a manifestation of the increase in
diastolic flow, a sign of the ‘brain–sparing effect’
 of chronic hypoxia, and results in decreases in Doppler
indices of the middle cerebral artery (MCA) such as
 the PI. Reduced MCA PI or MCA PI/umbilical artery PI
(cerebroplacental ratio) is therefore an early sign of
 fetal hypoxia in SGA fetuses.162–
 An axial section of the brain, including the thalami
 and the sphenoid bone wings, should be obtained and
 magnified.
 Color flow mapping should be used to identify the circle
 of Willis and the proximal MCA .
 The pulsed-wave Doppler gate should then be placed at
 the proximal third of theMCA, close to its origin in the
 internal carotid artery (the systolic velocity decreases
 with distance from the point of origin of this vessel).
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• The angle between the ultrasound beam and the direction
of blood flow should be kept as close as possible
to 0◦ (Figure 6).
• Care should be taken to avoid any unnecessary pressure
on the fetal head.
• At least three and fewer than 10 consecutive waveforms
should be recorded. The highest point of the waveform
is considered as the PSV (cm/s).
• The PSV can be measured using manual calipers or
autotrace. The latter yields significantly lower medians
than does the former, but more closely approximates
published medians used in clinical practice11. PI is
usually calculated using autotrace measurement, but
manual tracing is also acceptable.
 No systematic reviews of effectiveness of MCA Doppler as a
surveillance tool in high risk or SGA fetuses were identified. A
systematic review of 31 observational studies (involving 3337
fetuses) found that MCA Doppler had limited predictive
accuracy for adverse perinatal outcome (LR+ 2.79,
 95% CI 1.10–1.67; LR– 0.56, 95% CI 0.43–0.72) and
perinatal mortality (LR+ 1.36, 95% CI 1.10–1.67;
 LR– 0.51, 95% CI 0.29–0.89).16
 Reduce MCA Pi
 1 to 3 weeks before abnormal biophysical profile
 Use for timing delivery is limited
 Most studies investigating MCA Doppler as a predictor of
adverse outcome in preterm SGA fetuses have reported low
predictive value
 MCA Doppler may be a more useful test in SGA fetuses
detected after 32 weeks of gestation where umbilical artery
Doppler is typically normal
 In one study of 210 term SGA fetuses with normal umbilical
artery Doppler, MCA PI < 5th centile was predictive of
caesarean section for nonreassuring fetal status (OR 18.0,
95% CI 2.84–750) and neonatal metabolic acidosis, defined
as umbilical artery pH < 7.15 and base deficit > 12 mEq/L
(OR 9.0, 95% CI 1.25–395).173
 Based on this evidence it is reasonable to use MCA Doppler
to time delivery in the term SGA fetus with normal umbilical
artery Doppler.
A
 Ductus venosus Doppler has moderate predictive value
for acidaemia and adverse outcome.
 • The ductus venosus (DV) connects the intra-abdominal
 portion of the umbilical vein to the left portion of the
 inferior vena cava just below the diaphragm. The vessel
 is identified by visualizing this connection by 2D
 imaging either in a midsagittal longitudinal plane of the
 fetal trunk or in an oblique transverse plane through
 the upper abdomen.
• In early pregnancy and in
compromised pregnancies
particular care has to be taken to
reduce the sample volume
appropriately in order to ensure clean
recording of the lowest velocity during
atrial contraction.
 Observational studies have identified venous Doppler as the
best predictor of acidaemia
 What is the optimal gestation to deliver the SGA fetus?
RCOG
 In the preterm SGA fetus with umbilical artery AREDV
detected prior to 32 weeks of gestation, delivery
 is recommended when DV Doppler becomes abnormal or
UV pulsations appear, provided the fetus is considered
viable and after completion of steroids. Even when
venous Doppler is normal, delivery is recommended by
32 weeks of gestation and should be considered
between 30–32 weeks of gestation.
C
 If MCA Doppler is abnormal delivery should be
recommended no later than 37 weeks of gestation.
 Timing delivery is therefore a critical issue in order to balance
the risks of prematurity against those of continued
intrauterine stay; death and organ damage due to
inadequate tissue perfusion.
 Given the mortality associated with umbilical artery AREDV
alone delivery should be considered based on this finding
 alone after 30 weeks of gestation and recommended no later
than 32 weeks of gestation
FMF
 After 34 weeks; high PI in umbilical artery or high PI in ductus
venosus or low PI in MCA or AFI below 5
 31-33 weeks : absent end diastolic flow in UA or absenta
wave in DV or deepest pocket of AF less than 2 cm
 28-30 weeks: reversed a wave in DV or reversed end distolic
flow in UA and deepest pocket of AF less than 2 cm and no
movement
 Less than 28 :reversed a wave in DV ,and reversed end
diastolic in UA and deepest pocket of AF less than 2 cm
How should the SGA fetus be
delivered?
 In the SGA fetus with umbilical artery AREDV delivery by
caesarean section is recommended.
 In the SGA fetus with normal umbilical artery Doppler or
with abnormal umbilical artery PI but end–diastolic
velocities present, induction of labour can be offered but
rates of emergency caesarean section are increased and
continuous fetal heart rate monitoring is recommended
from the onset of uterine contractions.B