What do I need to know about Rh factor or Rh incompatibility?
Rhesus (Rh) factor is an inherited trait that refers to a specific protein on the surface of red blood cells. If your blood has the protein, you’re Rh positive — the most common Rh factor. If your blood lacks the protein, you’re Rh negative. Your health care provider can determine your Rh factor with a basic blood test. Your Rh factor doesn’t affect your health. However, your pregnancy needs special care if you’re Rh negative and your partner is Rh positive. During pregnancy — or, more likely, during delivery — your blood and the baby’s blood may mix. If you’re Rh negative and your baby is Rh positive, your body may produce Rh antibodies to fight the baby’s blood. The antibodies are generally harmless during the first pregnancy. However, if you have a subsequent pregnancy with an Rh positive baby, your Rh antibodies may attack the baby’s red blood cells. The subsequent Rh positive baby may develop Rh disease, a life-threatening condition that could require a blood transfusion through t
