The first Chapter in this thesis aims to present an adequate background information on the previous work. Short of introducing routine antepartum prophylaxis programme, the only avenues open to impact on the incidence of RhD alloimmunisation, were efforts to fine-tune the operation of the existing postpartum prophylaxis programme.  This included improvement of the accuracy of measuring the volume of transplacental bleeds, in order to ensure that sufficient dose of anti-D is administered to afford protection against sensitisation.  Chapter II discusses the results of a Kleihauer Quality Assurance Scheme in Scotland, and demonstrates that, this scheme was effective in bringing about a change in the practice of Kleihauer testing in Scotland, and introduction of greater standardisation and harmonisation of practice with trends towards improved test results. The data presented in Chapter III, provide data on the incidence of RhD alloimmunisation in Scotland and relate this incidence to similar results obtained using different methodologies and denominators.  These data show that there had been no significant changes in the alloimmunisation rates over the previous decade. Mortality due to Rh disease had been underestimated, due to reliance on registry data.  Combining registry data, information from the case notes of alloimmunised mothers and data from tertiary referral centre in Scotland, as set out in chapter IV demonstrated the true magnitude of fetal / neonatal loss in Scotland between 1987-1991 and provides some information on the long term sequelea of Rh disease.  A total of 20 fetal losses occurred over this period, several fold greater than suggested by the registry data. Finally, in collaboration with Health Economic Research Unit in Aberdeen University, the above information was utilised to assess the economic aspects of introducing routine antenatal prophylaxis.