Nikki -

Thanks for your input. I've read a few times about infection (not just GBS) causing a chemical release (I forget of what) that triggers labour and weakens membranes. I think it is one of those most sad effects of a bad infection, as you say perhaps when in combination with other factors. But there's nothing to be done about it in advance I wouldn't say. We can't all have abx all pregnancy! A sad rare fact of pregnancy.
Yes as I said, it's not exclusive to GBS infection. The thing is, I was completely asymptomatic so I don't know if I had a "bad" infection or not. My urine hadn't been tested since booking-in so there wasn't much I could have done in advance, except if I'd known the very subtle signs of dilation (which in retrospect I had), I could have had a cerclage sited to stop it and avoid the infection getting in. That's why I posted that info and link. But if I'd had a positive urine culture, well that would be another thing...
As for all pregnant women getting abx, I never suggested that, in fact I'd be dead against that as there is already a problem with resistance with GBS, BUT if it's present in urine I'd be doing something about that - whether by abx or natural means - just leaving it would be a damn risky strategy. Things can change within a matter of days though so I'd say the faster the treatment, the better.
Statistics are all very good and tidy but if you are that one-in-however-many things are a bit messier. I was throwing statistics around myself not so long ago.