Since the pioneering work of Donald and his first Lancet paper in 1958, the use of ultrasound in obstetrics and gynaecology has evolved rap idly. The introduction of grey scale techniques enhanced our ability to identify different tissues on the basis of their texture. However, it was the introduction of the linear array real-time scanner in the mid seven ties that changed ultrasound from being an "eccentric art form" to a readily available and usable technique. This led to the first repor...