Rh System

The Rh System  is a CODED CLINICAL ENTRY.

In addition to the antigens present in the ABO System, red blood cells sometimes have another antigen, a protein called the Rh factor.

• If the Rh factor is present, the PERSON's blood group is RhD positive;

• If the Rh factor is absent, the PERSON  is RhD negative.

This means that a PERSON  can be one of eight blood groups:

• A RhD positive (A+)

• A RhD negative (A-)

• B RhD positive (B+)

• B RhD negative (B-)

• O RhD positive (O+)

• O RhD negative (O-)

• AB RhD positive (AB+)

• AB RhD negative (AB-).

For further information on the Rh System, see the NHS website at: Blood groups.