A girl with the weight of 3100 g was born at home from her mother's third pregnancy. On the third day, the mother noticed small hemorrhages in the umbilical wound, as well as "red dots" on the selera of the child's eyes. The mother was not registered for prenatal care checkups. She is breastfeeding her baby as needed. Physical examination detects subconjunctival hemorrhages. Laboratory testing revealed that the hemoglobin levels were 155 g /L, the mother's blood group was B (III) Rh-positive, while the child's blood group was A (II) Rh-negative. What is the optimal tactics to prevent the progression of this condition in the child?