American Association of Blood Banks

View all recommendations from this society

Released April 24, 2014; Updated January 28, 2022

Don’t transfuse O negative blood except to O negative patients and in emergencies for women of child bearing potential with unknown blood group.

O negative blood is in chronic short supply due in part to overutilization for patients who are not O negative. O negative red blood cells should be restricted to: (1) O negative patients; or (2) women of childbearing potential with unknown blood group who require emergency transfusion before blood group testing can be performed.

In massive transfusions, most group O negative or ABO-unknown patients can receive O positive red blood cells.

These items are provided solely for informational purposes and are not intended as a substitute for consultation with a medical professional. Patients with any specific questions about the items on this list or their individual situation should consult their physician.

How The List Was Created

Recommendations were drafted by a work group led by AABB Director Jeannie Callum, MD. Ten draft statements were edited by the AABB Clinical Transfusion Medicine Committee, chaired by Aaron Tobian, MD. In order to identify the top five statements, a random sampling of AABB physician members working in the field of transfusion medicine in hospitals, as well as all members of AABB’s Clinical Transfusion Medicine Committee, were asked to rate the 10 draft statements. On a Likert scale, participants were asked to “indicate the importance of including each of the following transfusion-related statements in the Choosing Wisely campaign promoting the appropriate use of health care resources.” The final top five statements were approved by the AABB Board of Directors.

AABB’s disclosure and conflict of interest policy can be found at


The Chief Medical Officer’s National Blood Transfusion Committee (UK). The appropriate use of group O RhD negative red cells. Manchester (UK): National Health Service; 2008. 4 p.