Blood Grouping

Persons whose blood group needs to be known for medical reasons fall into three classes: blood donors, blood transfusion recipients, and pregnant women. Blood donors are almost exclusively grouped by the National Blood Transfusion Service. Relatively small numbers are grouped by the Greater London Red Cross Blood Transfusion Service and by individual hospitals. It practically never happens that a donor has to be grouped or a sample taken for grouping other than at a large transfusion centre of some sort. Apart from the most severe obstetrical haemorrhages, and uncontrollable haemorrhages due to accidental trauma, transfusions are never carried out away from hospitals. Such obstetrical and traumatic cases will, in general, be transfused with group 0, Rh-negative blood by " flying squads " without preliminary grouping. Hence blood grouping of recipients is always carried out in hospitals or is done for them by the laboratories of the National Blood Transfusion Service. The same applies to the direct matching between the blood of donors and recipients. The blood grouping of pregnant women is carried out for antenatal clinics by hospital laboratories or by the National Blood Transfusion Service, and the necessary samples are taken at the clinics. When a pregnant woman is not attending a clinic, her own doctor should arrange for the performance of the necessary tests either at the local hospital laboratory (as for other pathological tests) or at the Regional Blood Transfusion Centre. Local arrangements vary, but information about them can be obtained from the regional transfusion director or from the medical officer of health.