Blood Group in Dehradun

What is a Blood Group?

Blood grouping determines which antigens sit on the surface of your red blood cells. The ABO system assigns you to group A, B, AB or O depending on which antigens are present, and the Rh system adds positive or negative according to whether the D antigen is there. Both matter for the same underlying reason: if you receive blood carrying an antigen you lack, your immune system attacks the transfused cells, which can be rapidly fatal. This is why grouping precedes every transfusion and is followed by cross-matching against the actual donor unit rather than relied upon alone. The Rh part carries a second, quite separate importance in pregnancy. An Rh-negative woman carrying an Rh-positive baby can be sensitised by exposure to fetal cells and produce antibodies that, in a later pregnancy, cross the placenta and destroy the next baby's red cells. Anti-D immunoglobulin given at defined points prevents this almost entirely, which is why every pregnant woman's group is established early. Your group is genetically determined and fixed for life.

Why take this test?

Blood grouping is advised at the first antenatal visit for every pregnant woman, because the Rh result determines whether anti-D prophylaxis is needed and whether antibody screening must be repeated. It is required before any planned surgery or procedure where transfusion might be necessary, before blood donation, and in any emergency involving significant blood loss. It is worth knowing your group in advance simply as useful information, and many people have it done once as part of a health check. It is also relevant in newborns of Rh-negative mothers, and in investigating haemolytic disease. Because the result never changes, a single test is enough for life, though hospitals and blood banks will always retest before transfusing rather than accept a card or a previous report, and that duplication is a deliberate safety measure rather than an oversight.

• First antenatal visit, for every pregnant woman
• Before planned surgery or any procedure that may need transfusion
• Blood donation
• Emergency involving significant blood loss
• Newborns of Rh-negative mothers
• Once, as generally useful personal health information

FAQs: Blood Group in Dehradun