During the 1960s and 1970s, the fetoplacental unit was assessed by means of biochemical studies in the form of oestriol and human placental lactogen assays. With the advent of both real-time ultrasound and fetal heart rate monitoring, the accent on fetal assessment has changed. More recently (the late 1980s) the use of Doppler ultrasound has expanded the non-invasive assessment of the fetoplacental unit. This review discusses these modalities along with reports of randomized controlled trial assessments of these modalities.