Dopplers

Question 1

UA PI indications

Answer 1

Suspected or known SGA fetus
AC <5th percentile
>30% discrepancy between the head and AC
EFW <10th
EFW dropping percentiles by 30%
Maternal hypertensive disorders
Decreased fetal movements

Question 2

MCA PI indications

Answer 2

SGA but normal UA PI in a fetus after 34 weeks

MCDANIEL twin gestation with TTTS

Question 3

DV PI indications

Answer 3

Raised UA PI (.95th) and reduced MCA PI in preterm SGA

MCDA twin gestation with TTS or selective IUGR

Question 4

MCA Peak systolic Velocity Indications

Answer 4

Maternal-fetal isoimmunisation
Suspicion of fetal Anaheim’s
Unexplained hydrops
MCDA twin gestation with suspicion of TTTS or TAPS

Question 5

Abnormal MCA PSV

Answer 5

> 1.5MoM

Question 6

Mean uterine artery pulsatilla index

Answer 6

Bilateral notching after 24 weeks is abnormal

Question 7

Ductus venosus anatomy

Answer 7

Originates from UV before turns to the right
Posterior and cephalad
Enters IVC just below diaphragm
3 hepatic veins reach IVC in a funnel like structure
Contains oxygenated blood shunted to heart

Question 8

DV 3 phase waveform

Answer 8

S-ventricular systole
D-early diastole
A-atrial contraction

Question 9

DV shunting

Answer 9

Indicator of right-heart function and fetal response to hypoxia
30% of UV shunts through DV at mid-gestation, reducing to 18% after 30 weeks
In FGR, can be up to 60%
Augmented DV pulsation is a marker of fetal acidosis and increased risk of SB

Pre-terminally, elevated RV end-diastolic pressure causes an increase in reversal oof flow during atrial systole—absent to reversed a wave

Question 10

Normal MCA in a FGR baby with other abnormal dopplers

Answer 10

may be reassuring though this may represent a failure of fetal compensation