solution strengthThis is just an update in case any curious woman finds this thread from a search engine.
The studies I read, linked through gentlebirth.org, used a solution of .2% (.25% max) chlorhexidine. Hibiclense (available at Walgreens, CVS, etc) comes in a bottle with a 4% solution, so you have to dilute it accordingly.
Keep in mind, for those of us who are not math geniuses, that .25% is not the same thing as 25%..we're talking a less than 1% solution here.
Also, keep in mind that the studies used chlorhexidine in sterile water, and hibiclense contains fragrance and alcohol, so irritation may come from those...use the lowest dose and not too often.
You don't really need it until labor anyway, since the danger with GBS is the baby ingesting or aspirating it during it's travel through the birth canal. The pros of chlorhexidine are that it rapidly kills the bacteria and has the same effect as ampicillin, without effecting your whole body, just the vaginal tract.
Some women may use it before labor just to get a negative result on their GBS test, but I do advise anyone to be wise in their use because it will kill the good flora too, so you might just want to hold off until active labor.Then, every six hours (four if you want to do like the docs do with the abx).
And you can also politely refuse manual vaginal/cervical exams if you are postive or unsure with GBS, because this can deposit bacteria into the cervical opening.