10 Mind-Blowing Blood Type Secrets Your DNA Doesn't Want You to Know

5. Rh Factor

The Rh factor, also called the Rhesus factor, is an antigen that occurs in the blood of humans and other primates. The Rhesus factor is present in an estimated eighty-five percent of all blood for humans across the globe. Patients who have the Rhesus factor in their blood are classified as having a positive blood type. Those who do not have it have a negative blood type. While the lack of the Rhesus factor is not considered an illness and typically has no impact on a patient's health, it may affect a patient's health during pregnancy. Since a baby can inherit the Rhesus factor from either parent, issues might occur when an unborn baby is Rh-positive and the mother is Rh-negative. This is known as Rh incompatibility. Pregnant women normally have a screening test for this incompatibility during their first prenatal appointment. Women who have Rh incompatibility may need to be given several Rh immunoglobulin injections. The reason is to prevent the production of Rh antibodies during pregnancy.