Early in pregnancy, you will have your blood type checked (e.g., A+, A-, B+, etc.). The + or – indicates your Rhesus (Rh) status. We pay attention to Rh in pregnancy because if mom is Rh negative, we give her RhoGAM (or an equivalent product) near the 28 week visit, and possibly at the time of delivery if the baby is Rh positive. The reason we give this is so that the mother doesn’t form antibodies to the baby’s blood. If mom were to create her own antibodies to the baby’s blood, it could cause a fetal anemia and perhaps death in future pregnancies if the fetus were Rh positive. If mom is Rh positive, we don’t have to worry about any of this.