Umblical & uterine artery Doppler

1. Umblical & uterine
artery Doppler
Aboubakr Elnashar

2. I. Umbilical artery Doppler
Idea:
Umbilical Arterial Flow is normally of low
resistance.
In hypoxic states:
relative placental hypoxia:
reactive VC of umbilical artery:
higher resistance:
decrease in diastolic flow
Aboubakr Elnashar

3. Interpretation:
• Resistance index: best ability to
predict abnormal outcomes (RCOG,2002
Evidence level II)
• Enddiastolic flow
• Systolic/diastolic ratio
• Pulsatility index
• Diastolic average ratio
Aboubakr Elnashar

4. Doppler indices
Aboubakr Elnashar

5. • Resistance Index:
In normal pregnancy:
{progressive increase in end-diastolic velocity
{growth& dilatation of the umbilical circulation}:
Resistance index falls.
In fetal growth restriction and/or
preeclampsia:
> 0.72 is outside the normal limits from 26 w.
Aboubakr Elnashar

6. •End Diastolic flow
In fetal growth restriction and/or preeclampsia:
is 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.
Aboubakr Elnashar

7. •S/D
Should be <3.
Small increases in S/D= 3-5:
chronic intrauterine disease manifest by IUGR.
Not strictly useful:
{1. low sensitivity.
2. Gestation age dependent}.
Aboubakr Elnashar

8. Normal
Absent
Reversed
Aboubakr Elnashar

9. RED
Aboubakr Elnashar

10. RED
Aboubakr Elnashar

11. Absent
Reversed
Aboubakr Elnashar

12. Advantages:Advantages:
1. In low risk
No benefit on mother or baby
(The Cochrane Library, 2003)
Aboubakr Elnashar

13. 2. In high risk:
Reduction of
perinatal morbidity and mortality
number of antenatal admissions
inductions of labor
resources compared with CTG
(Grade A RCOG, 2002; The Cochrane Library, 2003)
Comparing FHR monitoring, FBP and umbilical artery Doppler:
only umbilical artery Doppler had value in predicting poor perinatal
outcomes in SGA
Aboubakr Elnashar

14. • Frequency of monitoring in SGA
fetuses with normal Doppler:
Once/2w (RCOG, 2002 Evidence level II)
• A 4-week U/S measurement interval was shown to be superior to a 2-
week interval, in terms of reducing the false –positive rate (Owen et al,
2001).
• Once/2w (Fortnightly) scans should be undertaken where
1. linear growth velocity is not maintained or
2. AC is below the third centile (IV)
Aboubakr Elnashar

15. II.Uterine artery Doppler
• limited use in predicting FGR and
perinatal death (Grade A, RCOG,2002).
• Abnormal uterine artery suggest:
maternal cause for the growth
restriction
• Normal uterine artery Doppler
suggest:
fetal cause
Aboubakr Elnashar

16. UAD: Normal
UAD: notch,
decreased diastolic
flow
Aboubakr Elnashar

17. Prediction of preeclampsia
(Uterine Doppler velocimetry)
• Persistence of a Diastolic
Notch in uterine artery
waveform after 24 w
• Systolic/diastolic ratio >2.6
• RI > 0.58 after 24 weeks.
Systole
Diastole
Aboubakr Elnashar

18. Aboubakr Elnashar