The nature of the relationship which female and male expectant parents develop during pregnancy with their unborn baby has both theoretical and clinical significance. It potentially provides a framework for improved understanding of many aspects of psychosomatic obstetrics, including reactions to foetal loss. Existing instruments designed to assess this relationship inadequately differentiate between attitude to the foetus per se versus attitude to the pregnancy state or motherhood role. The present paper presents a theoretical model of the subjective experiences of human attachment. This is utilized to develop a questionnaire to assess the antenatal attachment construct. Item analysis results in a 19-item maternal and 16-item paternal questionnaire with high levels of internal consistency. Each takes approximately five minutes to complete. Finally, the factor structures of the resultant questionnaires are explored.