that's not really how karma works, karma is based on what you do, not what happens to you.
Something like recompense might work, but the word is not very Shard-y.
Also I could see the laws about alcohol and other stuff that causes birth defects being very harsh just to prevent what you were talking about, either for reasons of it not being very nice to the kid who might end up not liking the trade-off or to prevent too many babies with magic being born to challenge the social structure.