Rh-negative B-type blood is prone to hemolysis with a second child, but it is not absolute and needs to be based on the blood type of the first child. If the first child is Rh-negative blood, there will be no stimulation of Rh antibody production in the mother, and the second child may be delivered successfully. If the first child has Rh-positive blood, Rh antibodies are produced in the mother’s body, and if the second child is still Rh-positive, an antigen-antibody reaction may occur and there is a greater risk of hemolysis. In mothers with Rh-negative blood, fetal Rh-positive blood can enter the mother’s body during the first pregnancy and stimulate the mother to produce antibodies, but in smaller quantities. When pregnant again, if still positive, fetal blood enters the mother’s body, it may produce a large amount of antibodies, which pass through the placenta and cause the fetus to undergo hemolysis. Immunoglobulin injections can be given under the guidance of a doctor to reduce the chance of hemolysis. If you have any other questions, it is recommended to consult a professional doctor for guidance.