The A- mother who has a child with the AB+ father is at risk for having a baby with hemolytic anemia of the newborn related to Rh isoimmunization. This occurs when the mother is exposed to a small amount of fetal Rh+ blood and develops antibodies against the Rh+ blood; these cross the placenta into the baby and attack the red blood cells. The offspring of the B+ mother, B- mother with the AB- father, and the A+ mother are not at risk for hemolytic anemia of the newborn with the information provided. Rh isoimmunization can occur following a transfusion, but this information is not provided in the question.