Date post: | 21-Jan-2018 |
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MAGDY ABDELRAHMAN MOHAMED
Lecturer of OB/GYN
2015
Intrauterine growth restriction.
Fetal doppler.
Macrosomia.
Fetal weight below 10th percentile for
gestational age.
Incidence: 3-5%.
1st suspicion due to decrease fundal level
below expected from gestational age.
Types:
Symetrical.
Asymetrical.
Etiology:
Fetal.
Maternal.
Placental.
Fetal doppler.
BPP.
NST & contraction stress test.
WHY
Take decision of termination at proper time.
The Doppler effect was first described by
Christian Johann Doppler (1803–1853).
First use of Doppler ultrasonography to study
flow velocity in the fetal umbilical artery
was reported in 1977.
Echoes from stationary tissues are the samefrom pulse to pulse.
Echoes from moving objects exhibit slightdifferences in the time for the signal to bereturned to the receiver.
pulse repetition frequency
(T2 –T1) phase shift with known beam / flow angle
can calculate flow velocity .
T1
T2
the angle q between the beam and the
direction of flow becomes smaller.
qThe angle of insonation
Flow velocity
Factors affecting doppler frequency
Umbilical artery.
Uterine artery.
Middle cerebral artery.
Benefit of Umbilical Artery Evaluation
Less experienced operators can achieve
highly reproducible results with simple,
inexpensive continuous-wave equipment .
With advancing gestation,
umbilical arterial Doppler
waveforms demonstrate a
progressive rise in the
end-diastolic velocity and
a decrease in the
pulsatility index.
Umbilical artery
S/D ratio:
2-3 in 2nd & 3rd trimester
PI :
1.5 – 2.0 in 2nd trimester
1.0 – 1.5 in 3rd trimester
RI:
Decreases with gest. In
late 2nd and 3rd it is around
0.5
Risk to Neonate
More admissions to NICU
Increase ICH
Increase Anemia
Increase Hypoglycemia
Increase long term permanent neurological damage
High ResistanceReversal of Diastole
Cordocentesis was carried out in 39 IUGR fetuses
80% Hypoxic
46% Acidemic
Absent / Reverse Diastolic Flow
12% Hypoxic
00% Acidemic
Positive Diastolic Flow
Umbilical artery 90% more sensitivethan CTG.
Interval between absence of enddiastolic flow & onset of latedeceleration was 3-12 days.
REFLECTS : TROPHOBLASTIC INVASION
END POINTS :
ELEVATED RESISTIVE INDICES (> 2 SD).
PERSISTENT DIASTOLIC NOTCHING.
UTERINE ARTERY
Normal
impedance to
flow the uterine
arteries in 1st
trimester. Normal
impedance to
flow the uterine
arteries in early
2nd trimester.
Normal
impedance to
flow the uterine
arteries in late
2nd and 3rd
trimester.
Normal uterine artery Doppler Abnormal uterine artery Doppler
Abnormal Uterine Artery
Doppler Velocimetry
Peak systolic velocity can be used in
diagnosis of fetal anemia.
Def:
Fetal weight more than 90th
percentile.
> 4000 gm.
Risk factor:
Diabetes.
obesity.
High parity.
Prolonged pregnancy.
Previous history of macrosomia.
Excessive weight gain during pregnancy.
Diagnosis:
Estimated fetal weight.
AC > 90th percentile.
Increased S.C. fat thickness.