The ability to identify true pre-term labour would be of considerable clinical benefit as electrical signals from the uterus, recorded using surface electrodes, may discriminate between labouring and non-labouring states in human pregnancy. A digital recording system for recording the electrical activity of the uterus has been developed and is described in this paper. A pilot study in which entire recordings in 21 women were subjected to power spectral analysis suggests that the relative power in two frequency bands (0.2-0.45 Hz and 0.8-3 Hz) changes as pregnancy progresses into early labour.