A prospective blind study of non-stress antenatal cardiotocography was undertaken in a group of 216 'high risk' pregnancies. The 'Cardiff' scores and the outcome of the pregnancies were compared subsequently. Low scores were associated with infants that were small-for-gestational age and fetal distress in labour, while high scores were associated with normal intrauterine growth. Although antepartum cardiotocography is predictive of fetal and neonatal outcome the extent to which its availability will prevent adverse outcome appears limited.