Well, now we're going to have something called RH incompatibility. And what that means is because these antibodies that were produced as a result of that first pregnancy are floating around in the bloodstream of the mother and because they're small enough, they can pass across the fetal membrane into the bloodstream of that fetus. Now, how is this a problem? Well, the fetus is assumed to be RH positive and that means it contains red blood cells that contain the antigen D. Now, when these antibodies travel through the membrane of the placenta and into the bloodstream of the fetus, they will bind onto the antigen D proteins of the red blood cells of the fetus. And once down, they will destroy, they will lyse the cell. And when the cell breaks, when it licenses, it releases dangerous chemicals into the bloodstream of that fetus.