Prevention of Rh haemolytic disease

Human immunization in developing countries: practical and theoretical problems and prospects

While measles, pertussis and tetanus were responsible during the early 1990s for nearly two million deaths in developing countries, no deaths were attributable to them in industrialized countries. More than 96% of global deaths by communicable diseases were also from developing countries. Respiratory infections ranked first in communicable morbidity at all ages. Even though vaccines of bacterial or viral origin or a prophylactic for passive immunization are produced in 24, 16 and 15 developing countries, respectively, none of the developing countries manufactures a plasma-derived prophylactic or biological response modifier. Nearly every country relies on import of one or more vaccines. The suboptimal performance of otherwise meritorious products has been due to faulty vaccine administration practices. Expanding populations, poverty and lack of education, cold-chain defects, and inadequate facilities for transport of vaccines to target populations in remote areas have been responsible for the poor performance of vaccines in the community. Mounting foreign debts and budgetary strains resulting from the care and prevention of AIDS/HIV have considerably strained national and international efforts to offer routine vaccinations in childhood and pregnancy. This dismal situation could be tackled through research to obtain environmentally stable products for prophylactic use and monoclonal antibody formulations for passive immunization, and through international financial and technical support. All countries should exercise some technical control of the quality of imported and indigenous vaccines during their use for curative or prophylactic purposes. The involvement of private clinicians in immunizations would strengthen national efforts for control of communicable diseases including AIDS, but this is not enough if the local factors cited above are not improved.

Haemolytic disease of the newborn--the changing scene

Between 1950 and 1970 there was a steady decline in the number of infant deaths from rhesus haemolytic disease of the newborn in the Yorkshire Region but no decrease in the number of pregnant women with antibodies. Following the introduction of Rh prophylaxis in 1970, the number of pregnant women sensitized has decreased by 70% and the number of infant deaths by 96%. The number of infants requiring exchange transfusion has also decreased by 70%. During the years 1980 to 1983 there were 163 new cases of maternal sensitization to the D antigen in the Yorkshire Region, 36 were due to failures of administration, 75 were failures of protection and 26 were in primigravidae. Eighteen of the failures of administration occurred after abortion, nine of which were surgical terminations. Antenatal prophylaxis may well have protected 64 (40%) of these 163 women. The number of pregnant women with antibodies other than anti-D now exceeds those with anti-D. The effect of these changes in incidence and clinical severity on the management of Rh D negative pregnant women is discussed.

Frozen recovered red cell boosting of female donors for anti-D-production

A selected group of women previously immunized in pregnancy by the Rh(D) antigen were boosted with 0.5 ml of Rh(D)-positive frozen recovered red cells from an accredited donor panel. The response was prompt and sustained and increased the anti-D content by almost 10-fold. In spite of the reduced rate of clinical immunisation to the Rh(D) antigen, it was possible to recruit females with anti-D, acquired in pregnancy, for secondary boosting and a programme is recommended which maximizes efficiency and safety.

Detection of fetomaternal haemorrhage by an immunofluorescence technique

An inexpensive and simple technique for assessing fetomaternal bleeds in cases of Rh(D) incompatibility is described. The method is unlikely to replace the acid elution technique, but it may be of use in cases where results are in doubt owing to the presence of F cells of maternal origin.

Computerized histories facilitate patient care in a termination of pregnancy clinic: the use of a small computer to obtain and reproduce patient information

An inexpensive microcomputer has been programmed to obtain histories from patients attending a pregnancy termination clinic. The system is nurse-interactive; yes/no and multiple-choice questions are answered on the visual display unit by a light pen. Proper nouns and discursive text are typed at the computer keyboard. A neatly formatted summary of the history is then provided by an interfaced printer. The history follows a branching pattern; of the 370 questions included in the program, only 68 are answered in the course of an average history. The program contains numerous error traps and the user may request explanations of questions which are not immediately understood. The system was designed to ensure that no factors of anaesthetic or medical importance would be overlooked in the busy out-patient clinic. The computer provides a much more complete history with an average of 42 more items of information than the pre-existing manual system. This system is demanding of nursing time and possible conversion to a patient-interactive system is discussed. A confidential questionnaire revealed a high degree of consumer acceptance.

A case for the antenatal administration of anti-D immunoglobulin to primigravidae

The value and practicability of introducing an antenatal anti-D immunoglobulin programme is a matter of controversy. Those in favour of the programme claim it is the only procedure available which will reduce still further the incidence of Rh sensitisation. Opponents claim it is not cost-effective. An analysis of data collected in the Yorkshire region points to the value of at least giving anti-D antenatally to all Rh-negative primigravidae and, if the baby is found to be Rh-negative, administering anti-D antenatally in the second pregnancy. Mothers developing anti-D antibodies in their first Rh-positive pregnancy are major contributors to the number of infant deaths due to Rh haemolytic disease of the newborn. When anti-D immunoglobulin is given to a mother with no demonstrable antibodies and she develops Rh antibodies in her next Rh-positive pregnancy, the prognosis for the child is good and "failures of protection" of anti-D immunoglobulin rarely result in infant deaths due to Rh antibodies.

Haemolytic disease of the newborn in Western Australia 1974 to 1976

The prophylactic use of anti-Rh (D) immunoglobulin has resulted in a marked decline in the incidence of Rh haemolytic disease of the newborn (HDN) since its introduction in 1968. Nevertheless, cases still occur. Those recorded in the metropolitan area of Western Australia in the 3 years, 1974 to 1976, have been studied in detail. There were 29 cases of ABO haemolytic disease, among which there were no deaths, and 56 cases of Rh haemolytic disease with 9 perinatal deaths. Nearly half of the mothers of the infants with Rh HDN were first immunised before anti-D became available; a quarter had not been given anti-D when it was required, and a few had formed Rh antibodies in their first pregnancy or despite treatment with anti-D.