###Human: My fiancee is B positive and I am O negative. Should I expect any pregnancy complication in future? ###Assistant: Hello. There would be no complications during the first pregnancy but may occur in the subsequent ones due to isoimmunization phenomenon. It is a problem which arises if the mother is having negative blood group and baby is having positive blood group. But treatments are available, so you have nothing to worry about it. I hope it has helped you. If you require any further queries, please do not hesitate to contact me.