No Periods, Period: While the Imperials have by and large abolished menstruation, it’s not due to any of the wacky supernatural, etc., extreme versions (found under Menstrual Menace), or even to the analog of our peculiar cultural ick on the topic.  The biotechnologists did it for reasons amounting to the traditional “we do what we can, because we must”, and the marketers successfully pitched this particular biomod all over the place on the grounds that it’s, as the Real Life section of the latter trope page pointed out at the time this was written, annoying and inconvenient.

And, as you may recall from Harmony Versus Discipline, mainstream Imperial culture generally think that the argument from “it’s natural!” is good for a laugh, but never worth taking seriously.