In this thesis the following research objectives were addressed:
To calculate umbilical venous volume flow from cross-sectional area and flow velocity
measurements with emphasis on: (i) the reproducibility of component measurements;
(ii) normal and abnormal fetal development, the latter also relative to umbilical artery
velocimetry.
To establish: (i) reproducibility and normal values for fetal liver volume as obtained by 3-
dimensional ultrasound; (ii) its significance in identifying fetal growth restriction relative to
head and upper abdominal circumference; (iii) its significance in identifying accelerated
growth in fetuses of insulin dependent diabetic mothers.
To determine: (i) normal values for fetal brain/liver volume ratio relative to gestational age;
(ii) the relation between fetal brain/liver volume ratio and umbilical venous volume flow
during normal and abnormal fetal development with emphasis on fetal growth restriction.
To establish: (i) fetal behavioural state dependency of umbilical venous volume flow in late
third trimester normal pregnancy; (ii) the impact of maternal plasma expansion and
antihypertensive treatment on umbilical venous volume flow in pre-eclampsi
