Much as I dislike most of the Star Trek novels (the sole exception being Andy Robinson's wonderful A Stitch In Time), I'll admit to kinda sorta liking Una McCormack's Enigma Tales. There is a minor character who is part Bajoran, so far back that she is able to pass as a Cardassian. There is narrative explaining that not only were Cardassian/Bajoran children common, steps had to be taken to prevent them.