ABORh

ABORh is the combined designation of an individual’s ABO blood group and Rh(D) antigen status. It is a standard label used in blood transfusion services and obstetrics to determine compatibility between donor blood and a recipient, and to assess risks during pregnancy.

The ABO system classifies red blood cells by the presence of A or B antigens. Type A has A antigens, type B has B antigens, type AB has both, and type O has neither. Naturally occurring antibodies in plasma typically include anti-A and/or anti-B, which can react with transfused blood of incompatible ABO type. The Rh system centers on the D antigen; individuals are Rh-positive if the D antigen is present, and Rh-negative if it is absent.

Testing and designation: blood typing uses forward typing (cells tested with anti-A and anti-B reagents) and often reverse typing (serum tested against known A or B cells). A full ABORh designation is written as a person’s ABO type plus Rh status, such as A+, O−, AB+, or B−.

Clinical significance: Transfusion safety relies on ABO and Rh compatibility to minimize immune reactions. ABO incompatibility can cause severe transfusion reactions, while Rh incompatibility is a central concern in pregnancy. Rh-negative mothers carrying an Rh-positive fetus may receive Rh immune globulin to prevent maternal sensitization.

Special considerations: Some individuals have weak D or variant D antigens; laboratory policies may classify such individuals as Rh-positive or, in obstetric risk assessment, treat them conservatively as Rh-negative.

Limitations: ABORh does not capture other clinically important blood group systems (such as Kell, Duffy, Kidd) that can influence transfusion outcomes; extended antigen typing may be used when indicated.