1. USS tests of fetal wellbeing

2. USS tests of fetal wellbeing
Amniotic fluid assessment
Biophysical profile
Umbilical artery doppler
Umbilical vein doppler
(Uterine artery doppler)
(Mean cerebral artery (MCA) doppler)

3. Amniotic Fluid assessment
Must not contain umbilical cord
Deepest pocket
<2cm (oligo) or >8cm (poly)
AFI
<5th centile for gestational age (oligo)
>95th centile for gestational age (poly)
<5.1cm
Subjective assessment by experienced operator

4. Indications
IUGR
Reduced fetal movements
Post dates pregnancy

5. Biophysical Profile History
Screened out anomalies
Alternative to Oxytocin Challenge Test Contraction Stress test
Arbitrary Scoring-no reason for the “weighting” some components maybe more important than others
Limited evidence to support its use
Normal result useful for 24 hours

6. Indications Post dates pregnancy IUGR Reduced fetal movements
Maternal hypertension

7. Parameters of Biophysical scoring
CTG
2 accs with mvmts in 20mins
FBMs
>1episode of 30s in 30min-not continuous
Gross body/limb mvmts
3 mvmts in 30mins-continuous
Tone/posture
1 episode flexion-extension-flexion of limb,opening hand, mouth, trunk rotation
AFV
1pool >2cms X 2cm

8. Tips for best assessment process
Do CTG first
Assess fetal state, do when fetus “awake”
Transverse fetal abdomen image with limbs
Score out of 10 - without CTG it is incomplete
USS part 0,2,4,6 or 8/8
6 or 8/8 normal
BUT for amniotic fluid ALWAYS an abnormal result

9. DOPPLER IN OBSTETRICS Flow velocity waveform-spectral display
Influenced by
cardiac function
vessel wall characteristics
viscosity
downstream vascular arrangement

10. DOPPLER IN PREGNANCY KEY POINTS
Need to understand basic principles
Is user dependent
Established roles fetal welfare assessment
assessment of anaemia
fetal echocardiography
Potential roles screening for preeclampsia
uses for venous doppler
Fetal circulation has low resistance throughout
absent or reversed velocities abnormal

11. UMBILICAL ARTERIAL DOPPLER
Mid portion of cord
In fetal quiescence
Use RI or PI
Progressive fall in resistive indices throughout normal pregnancy
Angle, sample volume important
Extremes of fetal heart rate will affect result

12. S = peak systolic frequencies D = least diastolic frequencies
S-D/S = resistance or Pourcelot index
S-D/mean = Pulsatility index
(S/D = s d ratio, cannot describe AEDV )
These are gestation dependent the trend is important

15. Use of Umbilical Arterial Doppler in high risk pregnancy (preeclampsia and SGA)
30% reduction in perinatal death
40% reduction in admissions
 deliveries< 34 weeks
No differences in C/S or fetal distress in labour
Cochrane review2000

16. Fetal growth restriction
Fetal “overgrowth”

18. Normal Spiral Arteriole
Thin walled
Abnormal Spiral Arteriole
Thick walled

20. Umbilical Doppler

21. FETAL VENOUS DOPPLER Venous Doppler
a marker of fetal cardiac dysfunction
influenced by fetal behavioural state esp FBM
Umbilical vein non pulsatile
pulsatile decreased forward flow at end diastole
Ductus Venosus “M” shaped waveform
reversed velocities abnormal
proposed uses TTTS
aneuploidy screening 1st T
anaemia

23. FETAL DOPPLER SUMMARY Umbilical artery well assessed
Trend through gestation important
Absent end diastolic velocities or reversed velocites always abnormal
Doppler does not tell when delivery should occur
Later in gestation fetus less tolerant of abnormal Doppler
Pulsatile umbilical vein may be preterminal

24. Uterine artery assessment

25. UTERINE ARTERY FLOW VELOCITY WAVEFORMS Upper panel normal waveform Lower panel abnormal with notching

26. Uterine arterial doppler a problem of a low prevalence condition
Poor predictor of preterm birth
Ultrasound Obstet Gynecol Sep;24(4): Second-trimester uterine artery Doppler and spontaneous preterm delivery. Cobian-Sanchez F, Prefumo F, Bhide A, Thilaganathan B.
Poor predictor of PET, FGR P.N.Mortality.
BJOG Feb;107(2): How useful is uterine artery Doppler flow velocimetry in the prediction of pre-eclampsia, intrauterine growth retardation and perinatal death? An overview. Chien PF, Arnott N, Gordon A, Owen P, Khan KS.

27. USS tests of fetal wellbeing
Amniotic fluid assessment
Biophysical profile
Umbilical artery doppler
Umbilical vein doppler
(Uterine artery doppler)
(Mean cerebral artery (MCA) doppler)