Women in this study wil receive L. reuteri Prodentis (L. reuteri DSM 17938 & L. reuteri ATCC PTA 5289 ) at a dose of 2x10^8 Colony Forming Units (CFU). One lozenges is to be taken twice per day (one in the morning and one in the afternoon) giving a total daily dose of at least 4x108 CFU/day since randomization until delivery. The control group will receive placebo lozenges which contains identical ingredients except for lacking the bacteria. One lozenges is to be taken twice per day (one in the morning and one in the afternoon. The study product will be kept refrigerated (+20 - +80 C)