Is there not, perhaps, a Big Contextual Problem here?
Quite a good article on sex education in the UK in today's Guardian G2 - though I am wincing away from looking at any Comment is Free feedback on it.
However, is the parlous state of sex ed really detachable from wider issues of national culture and Brit weirdness about sex? and while I can see that better sex ed might do something to shift this, maybe, over a long duree, it's not happening in a vacuum.
Anyway, a lot of what it is saying could have been said of any given decade over the past hundred years or so: some schools were doing excellent and sensible work, others were doing minimum or nothing at all, 'the parents ought to be doing this' but they weren't and didn't know how, people were saying it was a good idea to start before puberty with the basic facts, and action was constantly being stymied by fear of the Daily-Mail-tendency to start frothing at the mouth over the entire concept and one person with an agenda could wreak serious derailment of programmes.
Having written on the history of UK sex education, it's not even an 'and then... and then... and then narrative': it's Groundhog Day deja-vued all over again.