“…The feto-placental circulation was almost neglected until Doppler ultrasound was proposed as an early risk assessment tool (Fitzgerald and Drumm, 1977). The easy and routine acquisition of in-vivo data provided the opportunity to investigate and validate various aspects of the fetal circulation, such as the haemodynamics of the umbilical cord (Bracero et al, 1989, Giles et al, 1986, Trudinger et al, 1985, Gill, 1979, Fitzgerald and Drumm, 1977, insights regarding the villous tree function and development (Guiot et al, 1992, Thompson and Stevens, 1989, Reuwer et al, 1986 and the understanding of the complete fetal circulatory system (Kiserud andAcharya, 2004, Fitzgerald et al, 1984). However, Doppler ultrasound cannot provide in-vivo information on the flow at the terminal vasculature due to limits of resolution.…”