An analysis of the efficiency of a Rhesus haemolytic disease prophylaxis programme

A method of implementing the anti-D prophy-laxis programme is described and its efficiency is studied by examination of the records of 889 Rhesus-negative. mothers. During one calendar year only eight (0 9 %) cases were found where there was failure to follow the correct procedure and to administer anti-D. Sixty-two point five per cent of the mothers who were given anti-D received it within 24 hours and all but 3 % within 48 hours. Methods of improving the programme are discussed. INTRODUCrION The original suggestion that injection of passive anti-D might prevent Rhesus immunization (Finn, 1960) has been amply justified in practice (Clarke et al., 1966; Freda, Gorman, and Pollack, 1966; Chown et al., 1969). Anti-D must be given in a dose appropriate to the volume of fetomaternal trans-fusion of Rhesus-positive blood, and also within 24 hours. An apparent failure of anti-D prophylaxis may be seen following fetomaternal haemorrhage at therapeutic or spontaneous abortion (Bowman, 1970a), and it is now the policy to give Rhesus-negative women anti-D at the time of such abortions. True failure of anti-D to protect from immunization does occur. Using the data collected by Clarke (1970), 13 (1 1 %) of 1,139 women were immunized, despite receiving anti-D at the end of the second pregnancy. The reason for this could be either an exceptionally large transplacental haemorrhage, or that the mother has been primed by the baby but that antibodies are not yet detectable at the time of delivery. The chief remaining reasons for a woman to develop Rhesus D antibodies are now failure to identify a patient at risk and/or failure to give anti-D. This aspect of 'failure ' has received little attention, but Bowman (1970b) found that 13 % of urban and 73 % of rural women at risk failed to receive anti-D, giving an estimated overall failure rate in Manitoba of around 25%. It was therefore decided to evaluate the efficiency of the anti-D programme in this hospital, which handles a quarter of the deliveries in a city where over 90 % of the total births occur in hospital