Doppler ultrasonography has an established role in monitoring of the following pregnancy complications
Intrauterine fetal growth restriction
Twin-to-twin transfusion syndrome
Which of the following is true regarding use of umbilical artery (UA) doppler in IUGR pregnancies?
Abnormal UA doppler directly correlates with a lower number of placental arteries per high power field
Abnormal UA doppler predicts fetal compromise with a lead time of 3 days after diagnosis
Diagnosis of abnormal UA doppler ultrasound affords time for useful interventions to be instituted to prolong pregnancy
Serial UA dopplers should be used from 32 weeks in high risk pregnancies
Absent end-diastolic flow in the umbilical artery is a trigger for delivery in a fetus <32 weeks
There is good RCT evidence for the use of fetal venous dopplers in the management of IUGR
Regarding the Middle Cerebral Artery (MCA) doppler in IUGR, which of the following are true?
MCA doppler assessment is of similar efficacy in both IUGR-affected pregnancies and the prediction of fetal anaemia in Rhesus isoimmunisation
In IUGR there is 'brain sparing' effect, leading to an increased diastolic flow, hence reduction in PI.
The MCA PI/ UA PI ratio (cerebro-placental ratio) is more sensitive than either measurement in isolation
MCA doppler is equally useful in both early and late-onset IUGR
The role of the Ductus Venosus in IUGR. Select the true answers.
DV doppler acts as a marker of cardiovascular deterioration
Absence or reversal of A-wave in early IUGR is a strong predictor of fetal acidaemia
There are clear RCT data and consensus around use of DV and timing of delivery of the IUGR fetus
Uterine artery doppler at 20-24 weeks gestation in low risk populations has a high predictive value for IUGR/pre-eclampsia
Finally, which of the following are true?
Aortic isthmus doppler abnormalities may precede DV changes, often by one week
Umbilical vein doppler abnormalities may predict right heart failure and myocardial hypoxia
MCA PSV can predict the existance of moderate to severe fetal anaemia with a sensitivity of 100% and false positive rate of 12%