I have been hearing about this a lot lately and it has got me panicing. I have heard it happens when bacteria from the anus or anywhere else enters the vagina and that is can kill the baby, usually in the 2nd trimester. This is really bothering me as I have a weak immune system(2 immune disorders). I cannot have sex, go without showering, anything. I change my panties 2 times a day or I get worried. I cannot find anything about it online, so I am wondering... how common is this?