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Jehovah's Witnesses and blood transfusions of outdated medical beliefs. Dissident Witnesses say the Society's use of Leviticus 17:12 to support its opposition to blood transfusions conflicts with its own teachings that Christians are not under the Mosaic law. Theologian Anthony Hoekema claims the blood prohibited in Levitical laws was not human, but animal. He cites other authors who support his view that the direction at Acts 15 to abstain from blood was intended not as an everlasting covenant but a means of maintaining a peaceful relationship between Jewish and Gentile Christians. He has described as "absurd literalism" the Witnesses' use of a scriptural prohibition on