The Rh factor is a type of protein that's usually found on red blood cells. When you have this protein, you’re considered Rh positive. About 85% of people are Rh-positive. The rest are Rh-negative.

When you’re pregnant, you may learn that your baby isn’t your type — blood type, that is. Every person is born with a blood type — O, A, B, or AB. And they’re also born with a Rhesus (Rh) factor, ...

Your blood type is determined based on specific antigens present in your blood. You can find out your blood type by asking your doctor for a test, donating blood, or taking an at-home blood test. Your ...