Doppler in Obs

1. Effect of vasoactive medications on
uterine blood flow.
The following medications increases
EDV and lower resistance indices and
hence improve utero-placental
circulation:
•Betamimetics
•iv magnesium

2. •Alpha methyldopa and hydralazine
•Niphedipine
•NO donors

3. Persistence of Bilateral diastolic
notch after 24 w of gestation is
abnormal Increased Risk of –
preeclampsia
- placental abruption
- Existing or impending IUGR -
Increased rates of prematurity,
caesarean section, and low birth
weight Start treatment Aspirin -
Vitamins C/E - Low molecular
weight heparin
Previous or present history of
preeclampsia or any other maternal
disease like: - Maternal collagen
vascular disease - Maternal
hypertension - DM with vasculopathy
Previous child with IUGR

4. Unexplained high maternal alpha
fetoprotein level
High HCG levels.
Very high level of fetal care
•In high risk pregnancy not
in low risk pregnancy
•The test is considered
positive in cases of: -
Bilateral persistent diacrotic
notch - PI more than 95TH
Percentile
•Screening has high negative
predictive value : If PI of
both ut. arteries are normal
the patient is likely will not
develop preeclampsia or IUGR

5. Generally harmless

6. 50% of cases
Easily detected with CDS
No pathologic significance if the
CTG is normal

7. Up to 70% of the placental
tertiary villi should be
affected to show changes in
umbilical a. waveform
When 40% of the villi are
affected, IUGR will be
present

8. When pathology is seen in
umbilical artery examine all the
remaining vessels :
- MCA
- UMBILICAL VEIN
- DUCTUS VENOSUS
Detailed examination to exclude anomalies
and chromosome abnormalities
In normal pregnancy:

9. {progressive increase in end-
diastolic velocity
{growth& dilatation of the
umbilical circulation}: Resistance
index falls.
In IUGR and/or PET:
> 0.72 is outside the normal
limits from 26 w.
In IUGR and/or PET:reduced,
then absent (AED) or reversed
(RED) in severe cases
Absent or reversed: Fetal
distress is almost
certain:Immediate BPP or NST
or Delivery may be indicated
Should be <3.

10. Small increases in S/D= 3-5:
IUGR.
Not strictly useful: 1. low
sensitivity. 2. Gestation age
dependent
Every 14 days.in SFGA with
normal Doppler
More frequent: severe SGA
Twice weekly:
abnormal Um A D
(PI or RI > +2 SDs above mean
for gesage) and end–diastolic
velocities present
Daily: AED/RED
NORMAL FLOW

11. ABSENT DIASTOLIC FLOW
REVERSED FLOW
Comparing FHR monitoring, FBP
and umbilical artery Doppler: only
umbilical artery Doppler had value in

12. predicting poor perinataloutcomes in
SGA
In preterm SGA: limited
accuracy: should not be used
In term SGA: Normal Um A D,
an abnormal MCA D (PI < 5th
centile) has moderate predictive
value for acidosis at birth: used
to time delivery.

13. Enhanced fetal cardiac output
and
Decrease in blood viscosity:
Increased blood flow velocity
preferentially shunt blood to brain
fastermost pronounced MCA
PSV
More sensitive for predicting f
anemia than the ΔOD450
Alternative to serial
amniocenteses
Excellent noninvasive tool for
the monitoring of f anemia.

15. CPR = RI mca / RI pl = more than 1
It is very sensitive predictor of fetal
growth 80%
MCA is more sensitive to
hypoxia than umbilical
artery.
MCA response to fetal
hypoxia is instant.

16. High systole in MCA →
fetal anemia
High diastole in MCA →
brain sparing effect in fetal
hypoxia
Brain sparing : High diastolic
flow, decrease PI
When O2 deficit is HIGH PI
tends to rise ,which presumably
reflects development of brain
edema.
Reversal in MCA : cerebral
edema
In growth retarded fetus :
the disappearance of the brain
sparing effect

17. The presence of reversed MCA
flow is
a critical event for the fetus and
precedes fetal death
Moderate predictive value
used in: preterm SGA with
abnormal Um A D and to time
delivery
- 50 – 60 % oxygen rich blood from
placenta to right atrium via umbilical vein
DV sampling in 1st trimester
is only indicated if NT is
abnormal

18. DV sampling in IUGR fetus
is indicated if umbilical, MCA
or both are abnormal
when Tricuspid insufficiency occurs in cases of
[anemia – congenital defects-placental
insufficiency ] dysfunction of cardiac
hemodynamics will happen …… LEAD TO steady
decline in diastolic flow ……then Diastolic reverse
flow …..associated with abnormal CTG &
increased perinatal mortality
In cases of congenital heart
disease
Volume overload on heart induces
venous pulsations

19. Single pulsations is a sign of cardiac
decompensation
Double pulsations is a sign of severe
cardiac insufficiency