Transcript No Slide Title

Doppler Ultrasound in Daily Practice
Wesam Kurdi, FRCOG
Head, Section of Maternal Fetal Medicine
Department of Obstetrics & Gynecology
King Faisal Specialist Hospital & Research Center
Riyadh,Saudi Arabia
Uses of Doppler Ultrasound in Obstetrics
•Doppler in IUGR
•Doppler in fetal anemia
•Doppler in Multi-fetal pregnancy evaluation
•Doppler in the assessment of the fetal heart
•Doppler in fetal structural abnormalities
•Doppler in placental and cord abnormalities
•Doppler in early pregnancy evaluation
•Doppler in screening for chromosomal abnormalities
Practical Points
Factors affecting the waveform
• Fetal breathing
Practical Points
Factors affecting the waveform
• The indices are higher at the fetal than at the placental
end of the cord, usually free loop is used
• Gestational age: end-diastolic velocity increases with
advancing gestation
• Fetal heart rate: can effect Doppler indices, but within
the normal limits of the fetal heart rate (120 to 160 bpm),
the changes in the Doppler indices are not significant.
• Fetal behavioral states: no effect
Practical Points
Factors affecting the waveform
• Angle of insonation: the higher the angle, the smaller
the waveform, preferable to keep the angle of insonation
as close to zero as possible
Remember:
cos 0= 1
cos 30= 0.87
cos 60= 0.5
cos 90= 0
fd =
2f v cos
c
Effects of the angle
Good angle
Bad angle
UTERINE ARTERY DOPPLER
UTERINE ARTERY DOPPLER
UTERINE ARTERY DOPPLER
Notching by Gestation
Highest risk
Persistant bilateral notching after 24 weeks
Less risk
Unilateral notches
Normalization by 24 weeks
UTERINE ARTERY DOPPLER
Persistent notching at 24 weeks
Uterine Artery Doppler
Screening studies for the prediction of pre-eclampsia
7-33%
low
24-77%
Very good
Very good
CI, confidence interval; LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value; Prev, prevalence; Sens, sensitivity; Spec, specificity; SPR, screen positive rate.
Uterine Artery Doppler
Screening studies for the prediction of fetal growth restriction below the 10th centile
higher
Lower
Borderline IUGR more heterogeneous
CI, confidence interval; LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value; Prev, prevalence; Sens, sensitivity; Spec, specificity; SPR, screen positive rate.
Uterine Artery Doppler
Screening studies for the prediction of fetal growth
restriction below the 5th and 3rd centile
12-19%
Very good
CI, confidence interval; FGR, fetal growth restriction; LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value; Prev, prevalence;
Doppler Ultrasound in IUGR
Why is it important to diagnose IUGR?
IUGR are at increased risk of complications:
• Fetal hypoxia and acidemia
• 3-10 fold  risk of perinatal mortality and morbidity
• Long-term intellectual and neurological
impairment.
Perinatal/ Post-natal Problems
Asphyxia, Temperature instability, Hypoglycemia, Fetal Distress, Acidosis,
Meconium aspiration, Polycythemia, Impaired growth and development, Adult
disease: cardiac, diabetes
Umbilical Artery Doppler
Screening in High Risk Pregnancy
Cochrane Database 2000
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Reduces hospital admissions (OR 0.56, CI= 0.43- 0.72)
Reduces IOL (OR 0.83, CI=0.74-0.93)
Trend to lower Perinatal Mortality Rate (OR 0.71, CI= 0.5-1.01)
No difference for fetal distress (OR 0.81, CI= 0.59-1.13),
or CS rate ( OR 0.94, CI= 0.82-1.06)
Fetal and umbilical Doppler ultrasound in high-risk
pregnancies
Eighteen completed studies involving just over 10,000 women were included.
Perinatal deaths
IOL
Caesarean sections
Operative vaginal births
Apgar  7 at 5min
RR
0.71
0.89
0.90
0.95
0.92
95%CI
0.52 to 0.98
0.80 to 0.99
0.84 to 0.97
0.80 to 1.14
0.69 to 1.24
Numbers needed to treat
203
AUTHORS' CONCLUSIONS: Current evidence suggests that the use of Doppler ultrasound in
high-risk pregnancies reduced the risk of perinatal deaths and resulted in less obstetric
interventions. The quality of the current evidence was not of high quality, therefore, the
results should be interpreted with some caution. Studies of high quality with follow-up studies
on neurological development are needed.
Alfirevic Z, Cochrane Database Syst Rev. 2010
IUGR with normal UA Doppler
Neonatal and maternal outcomes
Twice-weekly
monitoring (n=85)
Fortnightly
monitoring (n=82)
Neonatal outcome
Gestational age at delivery (d, mean  SD)
264  13
268  12*
Umbilical artery resistance index at delivery (mean  SD)
0.63  0.08
0.61  0.06
Abnormal umbilical artery resistance index at delivery (No.)
Female sex (No.)
5 (6%)
43 (51%)
Birth weight (g, mean  SD)
Birth weight <10th percentile (No.)
Ponderal index (mean  SD)
1 (1%)
46 (56%)
2534  454
2587  412
47 (55%)
57 (69%)
2.42  0.29
2.40  0.28
Ponderal index <10th percentile (No.)
29 (34%)
39 (48%)
Admission to neonatal nursery (No.)
26 (31%)
28 (34%)
Neonatal hospital stay (d, median and range)
5 (0-66)
4 (1-27)
Acidosis at birth (No.)
4 (5%)
3 (4%)
Hypoglycemia (No.)
16 (19%)
18 (22%)
Maternal outcome (No.)
Spontaneous onset of labor
8 (9%)
21 (26%†)
Induction of labor
70 (82%)
54 (66%†)
Cesarean delivery
13 (15%)
11 (13%)
Cesarean delivery for fetal distress
7 (8%)
7 (9%)
Preeclampsia
4 (5%)
1 (1%)
Gestational hypertension
20 (24%)
13 (16%)
*p<0.05
†p<0.02
McCowan et al 2000 167 IUGR fetuses
Clinical Management of IUGR
How reassuring is a normal test result?
Stillbirth rate within one week of a normal test
NST
1.9/1000
(5861 patients)
CST
0.3/1000
(12656 patients)
BPP
0.8/1000
(44828 patients)
Modified BPP (NST + AFI)
0.8/1000
(54617 patients)
UA Doppler
0/1000
(214 patients)
Umbilical Artery Doppler and Poor Fetal Outcome
Sensitivity
Specificity
PPV
NPV
Abnormal outcome
79%
93%
83%
91%
SGA
75%
77%
32%
95%
FD, pH, Apgar, NICU
86%
68%
96%
69%
FD, pH, Apgar, NICU, Mec
82%
92%
81%
74%
Abnormal NST
93%
78%
8.4%
99.8
Fetal distress
70%
89%
31%
97.5%
CS for FD
9%
88.8%
21.6%
99.7%
1410 tests done
•Increased RI occur prior to changes on NST
•Simple, efficient
•Mean time 6 min vs 27 min for NST
Umbilical Artery Doppler
+ve EDF
-ve EDF
3%
14%
24%
<0.001
Cesarean Section
56%
96%
96%
<0.001
NICU
60%
96%
98%
<0.001
Severe RDS
3%
17%
41%
<0.001
Severe IVH
1%
9%
35%
<0.01
NEC
3%
5%
9%
0.2
IUFD
459 High Risk Pregnancies, Karsdorp et al, 1994
1126 cases of AEDV:
Stillbirth rate:
170/1000
ENMR
280/1000
cPMR
340/1000
Maulik, 2005
Reverse EDF
P
Can Umbilical Artery Doppler Predict
the Sick IUGR?
Parameter
AEDF
REDF
Gest age
C/S
Fetal distress
Bt Wt < 3rd
Acidemia
34 wks
77.6%
31.3%
13.4%
4.5%
29 wks
95.6%
60.4%
57.8%
20.8%
115 fetuses with AC < 5th
Doppler performed 24 hours before delivery
• Abnormal umbilical artery Doppler is more predictive of neonatal
outcome than EFW.
• If EDF present and PI > 2SD from mean, 90% will deliver vaginally.
A randomised trial of timed delivery for the compromised preterm fetus:
short term outcomes
GRIT Study Group, BJOG. 2003;110(1):27.
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Randomized controlled trial, 69 hospitals in 13 European countries.
Pregnant women with fetal compromise between 24 and 36 weeks, an umbilical artery
Doppler waveform recorded and clinical uncertainty whether immediate delivery was
indicated.
METHODS: The interventions were 'immediate delivery' or 'delay until the obstetrician is no
longer uncertain'. The data monitoring and analysis were Bayesian.
MAIN OUTCOME MEASURES: 'Survival to hospital discharge'
548 women (588 babies) recruited, outcomes were available on 547 mothers (587 babies).
Median time-to-delivery intervals were
Death prior to discharge
cesarean section
Immediate gp
0.9 days
10%
91%
Delayed gp
4.9 days
9%
OR: 1.1, 95% CI 0.61-1.8
79%
OR 2.7; 95% CI 1.6-4.5
MIDDLE CERABRAL ARTERY DOPPLER
Easy to study
Main branch of the circle of Willis
Carries 80% of blood flow to the ipsilateral cerebral hemisphere
Carries 3-7% of cardiac output throughout gestation
MIDDLE CERABRAL ARTERY DOPPLER
Relation to neurodevelopment
• Decrease MCA PI is an adaptive process protecting the
fetus against severe brain damage.
• 3 years follow-up failed to demonstrate neurodevelopmental
abnormalities with decreased MCA PI.
Scherjon 1998
• Drop in MCA PI may be protective against IVH but
prematurity is the greatest predictor.
Mari 1996
Performance of single Doppler measurement for
major adverse perinatal outcome at <32 weeks.
Sensitivity
Specificity
PPV
NPV
UA
59.1
69.7
32.5
87.3
MCA
95.9
47.2
30.9
97.9
UA
- better for screening
MCA
- reassurance if normal
Venous Doppler
The fetal venous system Doppler waveforms evaluates the fetal
heart compensation to severe growth restriction.
The commonly studied vessels include:
•Umbilical vein
•Ductus venosus
Relation between UA and UV
• AEDF in UA
no pulsation:
19% mortality
pulsation:
63% mortality
Intra-abdominal part is more sensitive than the free loop, pulsation in the
free loop is a very bad sign.
Progression of fetal growth restriction
Sequence of Doppler Changes in IUGR
Sequence of Doppler changes in IUGR
UA indices
Velocity
MCA resistance
Oligohydramnios
Ao indices
Absent EDF in UA and AO
DV and IVC velocity
Reverse "a" wave in DV
Possibly with
CTG changes
Brain sparing
Asymmetrical IUGR
Visualization of coronary circulation
Pulsatile UV
Constriction of cerebral circulation
Death within 96 hours
2 weeks prior
to CTG
changes
Arterial and Venous Doppler and Perinatal Death
Sensitivity
Specificity
PPV
NPV
100
50
42
100
MCA
60
29
23
67
UV
80
50
36
88
DV
80
93
80
93
UA
Ozcan et al 91 1998
Duration of persistent abnormal ductus venosus flow and its impact
on perinatal outcome in fetal growth restriction.
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171 patients with 1069 examinations.
Duration of an absent/reversed a-wave in the DV (DV-RAV)
Stillbirth
6 days
Intact survivors
0 days
P = 0.006
Major morbidity
0 days
P = 0.001
Duration of brain sparing
Stillbirth
19 days
Intact survivors
9 days
P = 0.02
Gestational age at delivery was a significant codeterminant of outcome for all arterial Doppler
abnormalities when the DV a-wave was positive.
When DV-RAV is found, this was the only contributor to stillbirth
DV-RAV for>7 days predicted stillbirth
100% sensitivity, 80% specificity, LR = 5.0, P<0.0001
Neither neonatal death nor neonatal morbidity was predicted by the days of persistent DV-RAV.
•
CONCLUSIONS: The duration of absent or reversed flow during atrial systole in the DV is a strong
predictor of stillbirth that is independent of gestational age. While prematurity remains the strongest
predictor of neonatal risks it is unlikely that pregnancy can be prolonged by more than 1 week in this
setting.
Turan OM, et al, Ultrasound Obstet Gynecol. 2011;38(3):295
Clinical Follow-up
Normal umbilical and MCA Doppler
NST and venous Doppler not indicated
Abnormal umbilical and MCA Doppler
> 34 weeks
< 30 weeks
delivery
Venous Doppler + NST
30-34 weeks
Normal
Steroids, close
observation
Abnormal
Consider
delivery
Individualize according to
findings, history and
neonatal facilities
Timing of Delivery
The risk of death or cerebral palsy reduces as each week
goes by, but if delivery is delayed until there is fetal
circulatory collapse (very abnormal venous blood flows), the
risk of death is also increased.
Harnington, Ultra OB Gyn 2000;16:399-401
TAKE HOME MESSAGES
• Umbilical artery Doppler can help to guide decision making and the
need for further fetal monitoring.
• Absent/ reversed EDF when linked with abnormal CTG increases the
risk of poor cognitive outcome in childhood.
• Arterial redistribution predicts hypoxemia.
• Venous Doppler abnormalities predicts heart failure.
• Venous system is the fine tuning area for planning the delivery.
• Appearance of a reverse a wave in the DV or pulsation in the
umbilical vein is a strong indication for delivery.
• Gestational age has the greatest influence on fetal wellbeing
Practical Points
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Overall survival of IUGR at < 26 weeks is <50%, intact survival is <50%.
Gestational age is more important than Doppler at < 26 weeks.
Intact survival are not much related to birth weight.
Outcome is better if less obvious CTG/ Doppler abnormalities are present.
Waiting reduces the risk of lung complications, but not NEC or IVH
Long term outcome: higher rates of disability in the earlier delivery groupmostly in < 30 weeks fetuses.
• Once severe redistribution occurs, further follow-up with arterial Doppler is
not very helpful for timing of delivery.
• Between 26 and 29 weeks: each day in utero has been estimated to
improve survival by 1-2%
• Arterial changes have been reported to last for up to 6 weeks, depending
on gestational age, presence of venous pulsation, and maternal disease.
Fetal Anemia
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Red cell immunization
Parvovirus infection
Massive fetomaternal hemorrhage
Hematologic disorders: Alpha-thalassemia, G6PD
Large placental chorioangioma
Twin-twin transfusion syndromes
Intracranial hemorrhage
What are the Effects of Severe Fetal Anemia
Prediction of Fetal Anemia
A variety of ultrasonographic parameters have been used to detect fetuses at
risk of anemia:
• Placental thickness: not been considered to be very reliable and
reproducible in clinical practice.
•
Hepatic length greater than or equal to the 95th percentile: the liver is
difficult to visualize and measure adequately, particularly when the fetus is
in an unfavorable position (back up or right side up).
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Splenic enlargement: a splenic perimeter greater than 2 SD has predicted
severe fetal anemia with a positive predictive value of 94%. It was found to
be an excellent predictor of severe fetal anemia in cases before the first
transfusion, with sensitivity and specificity of 100 and 94.7%, respectively,
but the predictive value was not as good in patients with prior transfusion or
with mild anemia.
•
Main splenic artery PSV: there was no risk of severe anemia with PSV
below the median for gestational age, but the prediction is not good for mild
anemia.
Prediction of Fetal Anemia
A prospective cohort study compared Doppler and ultrasound
parameters to predict fetal anemia in alloimmunized pregnancies.
Sensitivity
MCA-PSV
Intrahepatic umbilical venous maximal velocity
Liver length
Spleen perimeter
100%
83%
66%
33%
MCA-PSV is the best available noninvasive test in the
prediction of fetuses at risk of anemia
Prediction of Fetal Anemia
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Multicentric study the sensitivity of MCA-PSV for predictions of moderate and severe
anemia prior to the first cordocentesis:
Sensitivity
100%
False positive rates
12% for 1.50 MoM
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Multicenter trial for timing a cordocentesis:
MCA-PSV is an accurate method of monitoring pregnancies
Number of false positives increased following 35 weeks' gestation
•
Prospective study compared MCA-PSV with Delta OD 450:
Both procedures are useful in the prediction of fetal anemia
But Doppler ultrasound is less expensive and noninvasive than amniocentesis
Doppler and Fetal Anemia
Normal fetuses
Anemic fetuses
MCA MoM > 1.5 MoM MCA peak velocity
Sensitivity
False +ve
Positive predictive rate
Negative predictive rate
100%
12%
65%
100%
Management of Rh(-) Immunized Patients
+ve antibody screen
Paternal genotype
Negative
No further testing
(paternity!)
Heterozygous
Consider fetal
blood typing
Homozygous
Follow
protocol
The RhD gene was cloned, PCR for fetal RhD status can be
performed on amniocytes or CVS specimen, inaccuracy 0.3-2%
Fetal DNA in maternal circulation: 100% accuracy
Modern management of red-cell alloimmunization
• MCA-PSV should be performed
in fetuses at risk of fetal anemia
on a weekly basis for three
consecutive weeks.
• Cordocentesis is indicated when
the MCA-PSV value is over 1.5
MoM.
• If the MCA-PSV remains below
1.5 MoM a regression line has to
be obtained from the following
three values.
Repeat weekly
Repeat Q1-2 wks
Repeat Q2-4 wks
Can the Peak Systolic MCA Doppler Assessment Be Used
to Time Serial IUTs?
The decreasing sensitivity MCA-PSV after several IUTs has several
explanations:
• By the third IUT, most of the circulating red cells in the fetal
circulation are donor cells that contain adult hemoglobin.
• Correction of the fetal anemia through IUT raises the fetal hematocrit
level, which also substantially increases whole blood viscosity.
Both of these will slow the speed at which blood moves through the fetal
circulation.
The average drop in Hg following donor transfusion is 0.4gm/ day
Validity of MCA PSV in determining severe
anemia in previously transfused fetuses
Wesam Kurdi
Maisoon AlMugbel
Fatima AlAbri
Elham AlMardawi
Maha Tulbah
Khalid Awartani
King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
MCA PSV in previously transfused fetuses
Objectives
To assess if the correlation between the MCA PSV and fetal hemoglobin is
maintained in fetuses who received multiple IUT’s
Patients and Methods
• Retrospective analysis on all pregnant women who received IUT’s at King Faisal
Specialist Hospital (January 2006 to December 2010).
• Doppler measurement of MCA PSV performed before cordocentesis.
• MCA PSV and fetal Hb expressed as multiples of the median (MoM).
• MCA PSV ≥ 1.5 MOM used as a predicator for severe anemia (Hb ≤ 0.55 MoM)
MCA PSV in previously transfused fetuses
Results
• 28 pregnancies, non-hydropic fetuses; GA at 1st visit 24 + 4.6 wks
• Parity: 5.2 (range 1-11); Living children: 4.1 (range 1-8)
• 64% had IUTs in previous pregnancy
n
GA
Hb g/L
Hb ≤0.55
FPR
DR
Before 1st
28
22.6
57 (14-95)
57%
43%
100%
Before 2nd
25
26.9
59 (10-114)
48%
54%
92%
Before 3rd
21
29.2
78 (50-127)
33%
61%
78%
Before 4th-6th
30
31.9
80 (45-110)
33%
76%
81%
Any anemia, PSV cut-off 1.5 MoM
0%
81%
Any anemia, PSV cut-off 1.4 MoM
0%
91%
• GA at delivery: 36.3 wks; Delivery at >35 wks: 66%
• Survival rate: 83%; Postnatal mean Hb: 124g/L
MCA PSV in previously transfused fetuses
Conclusions
• In the prediction of severe fetal anemia by MCA PSV: The FPR
increases and DR decreases with increasing number of IUT’s
• Severity of anemia is reduced with repeated IUT’s
• Reducing the MCA PSV to 1.4 MoM after the 3rd IUT improves the DR
to 91%
• What should our end point be for mature fetuses: any anemia or
severe anemia?
Kell alloimmunization
• The mechanism of anemia in Kell alloimmunization is
in direct suppression of erythropoiesis in conjunction
with sequestration of sensitized red cells.
• Evaluation of at-risk fetuses with MCA PSV has a
sensitivity and specificity of 89% for the detection of
fetal anemia, similar to the detection of fetal anemia in
RhD alloimmunization.
How to Suspect/ Diagnose Other Causes of
Fetal Anemia?
• Severe anemia causes Hydrops
• All cases of fetal Hydrops: must check MCA PSV
Parvovirus B19 infection
• The measurement of MCA PSV predict fetal anemia
with a sensitivity of 94.1%.
• All cases with moderate and severe anemia were
detected either by MCA PSV alone or in combination
with real-time ultrasonography.
• A threshold of 1.29 MoM has been proposed; this will
lead to the detection of cases of mild anemia.
• Because frank hydrops has been reported to resolve
spontaneously in as many as 30% of cases, a threshold
value of the MCA velocity of 1.5 MoM is better for
timing of IUT.
Fetomaternal Hemorrhage
• An increased MCA-PSV has been reported in cases of acute
severe fetomaternal hemorrhage.
• In most of these cases, other clinical signs such as decreased fetal
movement or a sinusoidal heart rate pattern have also been
present.
• The suspicion of severe fetal anemia can assist in the decision for
early delivery, with blood immediately available for neonatal
transfusion in the delivery room.
• IUT in these cases has been successful only rarely because of the
continued passage of fetal blood into the maternal circulation.
KFSH&RC Experience in
Isoimmunization
Challenging Case:
Rh Isoimmunization with Glanzmann Thrombasthenia
1st pregnancy IUFD hydrops
2nd pregnancy: 6 intrauterine transfusions with pre-procedure
platelets transfusion and Trenaxemic acid, IOL and SVD at 37 weeks
3rd pregnancy: severe intraabdominal bleed following intrauterine
transfusion, found to have antiplatelet antibodies.
With modern management: only 3 transfusions were needed.
Conclusions
•Fetal anemia is commonly seen in our practice
•Anemia is seen both in immune or non-immune hydrops
•MCA-PSV is the new gold standard for the detection of fetal
anemia
•In Immune hydrops, we do not start intervention till MCA PSV
is  1.5 MoM
•After the third in-utero transfusion, we do not depend on MCA
PSV for predicting anemia or timing of transfusions
•Please remember to include MCA PSV in your scanning reports
in all cases of non-immune hydrops