The monitoring of fetal lambs in-vivo, has been previously carried out by using hard-wires. This work presents an alternative method for monitoring, by use of radiofrequency biotelemetry, with which there are no hard wires. With biotelemetry, a more "natural" recording may take place from the fetus. Long term, natural monitoring of fetal development has not been possible in the past.The design and implementation of a system capable of providing continuous, isolated monitoring is presented. The problems associated with the development and subsequent use of this system will be presented, especially the problem of noise.Data acquisition and analysis methods are also introduced and developed to suit the large amounts of information produced by the biotelemetry system.Analysed data from two fetal animals are presented and the significance of the reduced information is discussed.