The Rh factor is another antigen found on the surface of red blood cells. If present, the blood type is Rh positive; if absent, it’s Rh negative. It’s crucial during pregnancy - if an Rh– mother carries an Rh+ baby, it can cause complications like Rh incompatibility, affecting future pregnancies.

Key Notes

• Rh+ → Antigen present; Rh– → Antigen absent.
• Important for blood transfusions and pregnancy.
• Preventive injection (Rh immunoglobulin) is given to Rh– mothers.