Blood Rh Factor Calculator

The Rh (Rhesus) system is one of the most significant blood-group system out there. On their surface, our red blood cells have antigens (proteins that cover the red blood cells) called the Rh antigen which is also known as the D-Antigen, or RhD antigen, or Rh factor.
- If the Rh antigen is present, then the blood is Rh positive (Rh+).
- If the Rh antigen is not present, then the blood is Rh negative (Rh−).

The Rh factor is most important during pregnancy as a fetus bearing positive Rh and a mother with negative Rh may cause complications during pregnancy.