Blood transfusion of transfusing uncrossmatched blood, O-negative blood is used, followed by crossmatch as soon as possible. O-negative is also used for children and women of childbearing age. It is preferable for the laboratory to obtain a pre-transfusion sample in these cases so a type and screen can be performed to determine the actual blood group of the patient and to check for alloantibodies. This chart shows possible matches in blood transfusion between donor and receiver using ABO and Rh system. In the same way that the safety of pharmaceutical products is overseen by pharmacovigilance, the safety of blood and blood products
Jehovah's Witnesses and blood transfusions who are Jehovah's Witness would not administer blood transfusions to fellow dedicated members. As to administering transfusions to non-members, "The Watchtower" stated that such a decision is "left to the Christian doctor's own conscience." In 1982, a "Watchtower" article declared that it would be wrong for a Witness to allow a leech to feed on his/her blood as part of a medical procedure, due to the sacredness of blood. In 1989 "The Watchtower" stated, "Each individual must decide" whether to accept hemodilution and autologous blood salvage (cell saver) procedures. In 1990, a brochure entitled "How Can Blood Save Your Life?"