I am not a doctor but I can answer your question as I am RH-ve. My mother is rh-ve and my father is rh+ve. In my parents case, luckily my blood group was rh-ve.
If a girl has RH-ve & boy has RH+ve Blood Group factor (irrespective of A, B, AB, O), then there is about 50% chance that the child will be rh+ve. I such case, complication may occur. Dring pregnancy if child's blood and mother's blood mixes, mother's immune system starts to develop antibodies against RH factor. This may result in destruction in RBC as mentioned by dr.sachin.
But even in that case, it is possible to prevent such complications and the pregnancy is possible. This is because of the developments in the field of Science.