RH Factor/Blood Group

Rh factor is an inherited protein found on the surface of red blood cells. If your blood has the protein, you’re Rh positive. If your blood doesn’t have the protein, you’re Rh negative. The “+” or “–” you might see after your blood type refers to Rh positive or Rh negative.

Rh positive is much more common than Rh negative. Having a Rh-negative blood type is not an illness, and it usually does not affect your health. But it can affect pregnancy. Your pregnancy needs special care if you’re Rh negative and your baby is Rh positive. That’s called Rh incompatibility. A baby can inherit the Rh factor from either parent.

Your health care provider will advise that you have a blood type and Rh factor screening test during your first prenatal visit. This will show whether you are Rh positive or Rh negative.