Wondering what your baby's blood type will be? Blood type is inherited from both biological parents. There's no way to be sure what your baby's blood type is without a blood test, but you can narrow down the possibilities if you know your blood type and your partner's. Red blood cells have substances on their surfaces that vary from person to person. The particular substance on your own blood cells determines your blood type. There are two blood group classifications: the ABO system and the Rh system. Continue Reading