What I'm looking for is some precedent that the drug's effects are magnified in the next generation, even if the parents stopped taking the drug before conception. I'd like the parents to be minimally effected so that the drug can be widely used before major issues pop up in the children. The drug will have helpful traits that will make it seem like a good idea to take it in the first place. Ideally i'm looking for something that messes with the DNA of reproductive cells, but not so much the rest of the body, creating birth abnormalities in the children of drug users.
I've googled the effects of drug use on fetuses and mothers (lots of keywords- drugs on the unborn child, drug babies, crack babies, taking drugs before pregnancy, taking drugs during pregnancy) as well as looking for info on drugs that effect at the DNA level (can drugs change DNA, rewriting DNA with drugs) but haven't found any evidence of what I'm looking for. If it isn't a possibility I'll just got with OOOH! advanced technology and magic! but I'd really prefer some sort of factual "oh, this has been seen before with chemical x"
Thanks in advance.