User blog comment:IvyBushe/Muggle-born parents and their children./@comment-4836523-20130407134424/@comment-4836523-20130407134937

Muggle-borns are children with muggle parents or grandparents. So much as a muggle or muggle-born grandparent pollutes the blood. Two muggle-borns, both having muggle or muggle-born grandparents, would produce muggle-born children. It would take a pure-blood to make the children half-blood.