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Fetal Dopplers- A Review
Kemoria Granberry DO
Arterial◦ Umbilical◦ Middle Cerebral◦ Uterine
Venous◦ Ductus venosus
Types of Dopplers
Fetal-placental unit Progression
◦ DecreasedAbsentReversed Measurements
◦ S/D(Systolic to Diastolic) Ratio◦ PI (Pulsatility Index)
Uniformity◦ Waveforms vary along length of cord◦ Absence of fetal breathing◦ Uniform waveforms
Umbilical Artery
Why the MCA? Progression
◦ Increased EDFV◦ Decreased PI
Measurement◦ Peak Systolic Velocity◦ Pulsatility Index◦ Cerebro-placental ratio
Middle Cerebral Artery
Physiologic status of right ventricle Progression
◦ Decreased Absent Reversed flow in a wave Measurement
Uniformity?
Ductus Venosus
Progressive decrease in impedence throughout pregnancy
Abnormal trophblastic invasion Measurement
◦ Notch◦ PI
Uterine Artery
Q1: Should doppler ultrasound assessment be
performed in low risk and/or high risk
pregnancies as screening test for IUGR?
Umbilical dopplers◦ No◦ Goffinet et al
Meta analysis 1997 4 trials; n 11,275 Trials to date underpowered to determine utility of screening
Uterine dopplers◦ No◦ Chien et al
Meta analysis 28 trials ; n=3000 Abnormal result more likely to predict IUGR (liklihood ratio)
◦ Cnossen et al Meta analysis 61 trials; n= 41000 Abnormal results corelated more with high risk pregnancies, though
liklihood ratio remain high in low risk pregnancies as well
Q1
Q2: What are the benefits and limitations of
doppler studies of each vessel when
IUGR is suspected?
Umbilical Doppler◦ Significant reductions in IOL, CS, perinatal deaths◦ No validated interventions
Middle Cerebral Dopplers◦ May identify IUGR fetuses at risk for CS for NRFHT
and neonatal acidosis◦ May identify IUGR fetuses at risk for long term
neurodevelopment delay in presence of normal umbilical dopplers
◦ No validated interventions Venous Dopplers
◦ Identifies severely compromised IUGR fetus
Q2
Q3: What is the usual progression of doppler
abnormalities in fetuses with suspected IUGR? Is this
progression consistant/reliable?
Q3. Early – Brain sparing
◦ Inc impedence in UA ◦ Dec impedence in MCA◦ MCA normalization
Late – Heart Sparing◦ Inc flow through DV improve left ventricular
output◦ Increased Absent Reversed DV◦ Increased central venous pressure ◦ Umbilical venous pulsations
Validated in preterm idiopathic IUGR fetuses
Q4: What dopplers study regimen should be initiated for suspected
IUGR? What other antepartum testing may be helpful in this setting?
Q4. Initiate
◦ Viability ◦ Suspected IUGR – differentiate hypoxic growth
restricted fetus from non hypoxic small fetus Frequency
◦ Weekly, q 2-4 weeks, 3-4x’s a week◦ Determined by severity of doppler abnormality
Other testing ◦ Twice weekly NST with weekly AFI◦ Weekly BPPs
What interventions are available and should be considered based
on abnormal fetal doppler velocimetry studies?
Q5. Interventions
◦ BTMZ◦ Hospitalization◦ Timing of delivery◦ ANT
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