DOPPLER IN OBSTETRICS

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DOPPLER IN OBSTETRICS

• Dr.Dharmesh Patel
• MD(OBGY)
• CERTIFIED IN ADVANCE ULTRASOUND(ICOG)

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DOPPLER ULTRASOUND
Doppler ultrasonography is a non-invasive
procedure that uses detectable changes in high
frequency sound waves (2-20 MHz), based on
the Doppler effect, to create clear digital
images in real time. Doppler ultrasonography is
based on two basic principles1. Ultrasound
principleHigh-frequency sound wave aimed at a
stationary target will be reflected back and
detected. The machine then displays the distances
and intensities of the echoes on the screen,
forming a two dimensional image 2. Doppler
principle Echoes from moving target exhibit
slight differences in the time for the signal to
be returned to the receiver . It brings changes
in the sound pitch depending on the movement of
the object ( blood) in relation to the detector
(positive or negative shift)- the speed of sound
in blood is 1570 m/s)

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PRINCIPLES OF DOPPLER SHIFT
When the frequency of sound emitted from a
stationary source is fixed, and its insonation
angle is known, the Doppler shift (i.e. the
difference between the emitted and the reflecting
frequency) f D  2f0v cos?/c
where f D  Doppler shift, f0  frequency of
the transmitted beam, v velocity of sound
within the tissue, ? insonation angle c
speed of sound in tissue
.
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Quantitative Analysis of doppler indices
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A Higher-frequency Doppler signal (beam
aligned to the direction of ) B Less aligned
than A and produces lower-frequency Doppler
signal C The beam/flow angle is almost 90and
there is a very poor Doppler signal D The
flow is away from the beam and there is a
negative signal
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USES OF DOPPLER IN OBSTETRICS
Diagnosis of fetal hypoxia (acute or chronic)and
acidosis in pregnancy
Prediction of fetal growth and maternal pathology
For diagnosis of fetal discordance in multifetal
pregnancy
Diagnosing fetal anemia in Rh isoimmunisation
Diagnosis of congenital anomalies and tumors
Absolute velocities for precise fetal
echocardiography
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VEIN OF GALEN ANEURYSM
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RENAL AGENESIS
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SINGLE UMBILICAL ARTERY

• It is diagnosed by imaging the origin of
  umbilical artery adjacent to fetal urinary
  bladder.
• ASSOCIATIONS
• 1. Chromosomal defects(autosomal
  trisomies)
• 2.Cardiac and renal anomalies
• 3.Normal variant(1)

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CORD COILING AROUND NECK
Generally harmless. Multiple(gt2) loops of nuchal
cord observed in 3rd trimester are relevant
especially in breech presentation because then
External Cephalic Version is contraindicated
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Unilateral renal agenesis with MCDK
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Fetal Anaemia reflected by MCA-PSV
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WHO ARE THE NEEDY ONES
MATERNAL AND/OR FETAL CONDITIONS AT RISK OF
CHRONIC HYPOXIA ARE-COMMON MATERNAL
INDICATIONS-Hypertensive disorders of
pregnancy-Chronic renal disease-Maternal
diabetes-Antiphospholipid syndrome and related
autoimmune disease-Cyanotic heart
diseaseCOMMON FETAL INDICATIONS -Intrauterine
growth restriction (IUGR)-Reduced fetal
movement-Post date pregnancy-H/o previous IUD ,
still birth , IUGR , oligohydramnios -Raised
serum alpha protein
ACUTE HYPOXIA
Ante Partum Haemorrhage,Vasa Previa,Cord
compression
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Fetus

• Hypoxic fetus
• Hypoxic Hypoxia
• PIH
• Post maturity
• Severe Maternal Anemia
• Sickle cell anemia
• Anemic Hypoxia
• Immune Hydrops
• Non Immune Hydrops
• Ischemic Hypoxia (Acute)
• Cord Compression
• Accidental Hemorrhage
• Fetus of Diabetic Mother

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FETAL CIRCULATION
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Decrease uteroplacental perfusion
UTERINE ARTEY
Decrease fetal perfusion
UMBILICAL ARTERY
Fetal hypoxia and acidosis
MIDDLE CEREBRAL ARTERY
Redistribution of blood supply to vital organs
Late compensatation of heart
AORTIC ISTHMUS
Cardiac failure and fetal acidosis
DV,UMBILICAL VEIN
Fetal demise
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What Kind of Information on CD ?

• Utero placental circulation Predictive
• Uterine Artery Umbilical Artery
• Fetal Arterial Circulation Cut Off Line
• Redistribution of Blood brain Sparing Effect
• Fetal Venous Circulation - Decision
• Timing of Delivery
• Degree of acidemia Hypoxia

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Changes due to Hypoxia

• When gt 50 placenta is not functioning
• Mild Hypoxia Umbilical artery
• When gt 70 placenta not functioning
• Moderate Hypoxia -gt Compensatory redistribution
  in MCA
• When gt 90 placenta not functioning
• Severe Hypoxia -gt Failure of Compensatory
  redistribution - DV

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UTERINE ARTERIES

• REFLECTS TROPHOBLASTIC INVASION
• SITE AT CROSSING OF EXT.ILIAC VESSELS
• END POINTS
• ELEVATED RESISTIVE INDICES (gt2SD)
• PERSISTENT DIASTOLIC NOTCHING
• PRESENCE OF SYSTOLIC NOTCHING
• MAJOR LEFT TO RIGHT VARIATION

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Uterine artery
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Normal uterine artery waveforms
Normal impedance to flow the uterine arteries in
1º trimester
Normal impedance to flow the uterine arteries in
early 2ºtrimester
Normal impedance to flow the uterine arteries in
late 2º and 3º trimester
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Uterine Artery
Uteroplacental circulation
Normal
Abnormal
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UMBILICAL ARTERIES

• REFLECTS PLACENTAL OBLITERATION
• SITE FREE FLOATING LOOP
• AT PLACENTAL END
• AT FETAL END
• END POINTS
• ABSENT END DIASTOLIC FLOW
• REVERSED END DIASTOLIC FLOW

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UMBILICAL ARTERY FLOW
Characteristic saw-tooth appearance of arterial
flow in one direction and continuous umbilical
venous blood flow in the other.
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Normal Umbilical Artery
1º trimester Absent Diastolic Flow
early 2ºtrimester Low Diastolic Flow
late 2º and 3º trimester Resistance further
reduce, more diastolic flow
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Umbilical Artery - Abnormal
Umbilical arteries- normal
Umbilical arteries- high pulsatility index
Umbilical arteries- Absent end diastolic
velocity- very high pulsatility index.-
pulsation in the umbilical vein
Umbilical arteriesreversal of end diastolic
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Umbilical Artery
Normal
Abnormal
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REFLEX REDISTRIBUTION OF FETAL CARDIAC OUTPUT
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MIDDLE CEREBRAL ARTERIES

• REFLECTS CEREBRAL FLOW
• SITE ANTEROLATERALLY BETWEEN ANT.
• AND MIDDLE CEREBRAL FOSSA
• END POINTS RISING PI AFTER A NADIR

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Normal MCA waveforms
Circle of willis
Normal impedance to flow in first trimester
Normal impedance to flow in second trimester
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MIDDLE CEREBRAL ARTERY
NORMAL
ABNORMAL
Redistribution of flow
Negative flow in diastole
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CEREBRO-PLACENTAL RATIO(CPR)

• MCA PI/UMA PI
• Better predictor of brain sparing effect
• Normal value should be gt1.08

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Pathological changes in venous flows with
FGR

• INCREASED PLACENTAL RESISTANCE
• INCREASED AFTERLOAD TO
• RIGHT VENTRICLE(SYSTEMIC VENTRICLE)
• RV
  DECOMPENSATION
• TRICUSPID REGURGITATION
• BACK PRESSURE TRANSMITTED TO VENOUS SYSTEM

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DUCTUS VENOSUS

• REFLECTS ACIDOSIS
• SITE HIGH VELOCITY FLOW FROM UMB.VEIN TO IVC
• END POINTS ABSENT FORWARD FLOW IN
  DIASTOLE

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Ductus venosus flow
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Abnormal Ductus Venosus Flow
Ductus venosus reverse a waveform
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UMBILICAL VEIN

• REFLECTS MYOCARDIAL FUNCTION
• SITE ALONG WITH UMB.ARTERY
• END POINTS DOUBLE PULSATILE PATTERN

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UMBILICAL VEIN
ABNORMAL
NORMAL
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DESCENDING ABDOMINAL AORTA

• REFLECTS FLOW TO THE ABDOMINAL VISCERA AND
  LOWER LIMBS
• SITE AT DIAPHRAGM
• END POINTS PULSATILITY INDEXgt6

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NORMAL VALUES
VESSELS PI RI
Umbilical artery Early 2nd trimester (1.5-2) Term 1 (1-1.5) lt0.7
Middle cerebral artery At 28-32 wks (gt1.45) Term 1 0.7-0.9
Uterine artery 18-22 wks(lt1.2) If PI gt1.45 with b/l notching then it indicates severe ischaemia. 0.33-0.55
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Decrease uteroplacental perfusion
UTERINE ARTERY
Decrease fetal perfusion
UMBILICAL ARTERY
Fetal hypoxia and acidosis
MIDDLE CEREBRAL ARTERY
Redistribution of blood supply to vital organs
AORTIC ISTHMUS
Late compensatation of heart
Cardiac failure and fetal acidosis
DV,UMBILICAL VEIN
Fetal demise
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Typical progression of multi-vessel Doppler
studies with progressive placental
dysfunction- -Elevated umbilical artery S/D
ratio -Middle cerebral artery PI lt 5th percentile
(brain-sparing) -Umbilical artery - absent
diastolic flow -Umbilical artery - reversed
diastolic flow -Aortic isthmus-loss of forward
flow in diastole -Ductus venosus - elevated
pulsatility index -Ductus venosus - reversed
a-wave -Umbilical vein double pulsations -Umbilica
l vein triple pulsation with reversed a-wave flow
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AORTIC ISTHMUS
REFLECTS PERIPHERAL FETAL CIRCULATORY DYNAMICS
AND RELATIVE SYSTOLIC PERFORMANCE OF EACH
VENTRICLE
SITE LONGITUDINAL AXIS OF ARCH OF AORTA 3
VESSEL TRACHEA VIEW
END POINTS ABSENT OR REVERSE DIASTOLIC FLOW
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AORTIC ISTHMUS
 
PRINCIPLE
Cross Road between two parallel arterial systems.
It represents the only shunt between the aortic
and pulmonary arches as well as the
supradiaphragmatic (towards the brain) and
infradiaphragmatic (towards the placenta)
circulations.
Hence, any changes either in individual
ventricular performance or in peripheral vascular
resistances are reflected in the isthmic Doppler
flow pattern.
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3 VESSEL TRACHEA VIEW
LONG.AXIS OF ARCH OF AORTA
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Decompensation- aortic isthmus

• When the net flow in the AI becomes
  retrograde-Nutrient and O2 content of the LV
  drops -- increased risk for adverse childhood
  neurodevelopment in fetuses .

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Time to deliver

• Factors to decide time to deliver
• Degree of Prematurity
• NICU facility
• Degree of Hypoxia, acidemia, hepatic metabolic
  derangement

Challenge to weigh the risks and benefits of
interventions
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Time to deliver

• When you want to deliver?
• ? Mild to moderate Hypoxia
• ? Moderate Hypoxia with Late compensated Heart
• ? Moderate Hypoxia with early acidemia
• ?? Severe hypoxia with moderate to severe
  acidemia hepatic metabolic derangements

Best time when fetal redistribution mechanism
start failing
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TAKE HOME MESSAGE

• Multi vessel doppler study must for any
• IUGR fetus to know the oxaemia status of fetus

CPR is the better and early predictor of brain
sparing effect and redistribution flow
Use of Aortic isthmic doppler can help to deliver
child in late compensated stage rather than
decompensated stage
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MY MESSAGE
I WANT TO GIVE
I DON'T EXPECT
AT LEAST I CAN GIVE
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THANK YOU