The client's blood contains the Rh factor and the newborn's does not, and antibodies that destroy red blood cells are formed in the fetus.

The client's anti-A and anti-B antibodies cross the placenta and cause the destruction of the fetal red blood cells.

The client has a history of receiving a transfusion with Rh-negative blood.

The client's blood does not contain the Rh factor, so she produces anti-Rh antibodies that cross the placental barrier and cause hemolysis of red blood cells in newborns.