The composition of a woman’s vaginal microbial community may predict risk of preterm birth. According to a study published Aug. 17 in Proceedings of the National Academy of Sciences a specific bacterial pattern ups the risk of preterm delivery, and the longer the pattern persists, the greater the risk. The authors say the findings have important implications for pregnancy outcomes. Preterm birth is a sizable problem globally. In the United States alone there are approximately 450,000 babies born prematurely each year. Prior research suggests that at least a quarter of preterm births are associated with occult microbial invasion of the amniotic cavity, most often from the mother’s host microbiota. Given this link, the researchers analyzed the microbiomes of 49 pregnant women, 15 of whom delivered preterm. From 40 of these women (in the discovery cohort) the researchers analyzed the microbiota from 3,767 specimens (collected prospectively and weekly during gestation and monthly after delivery from the vagina, distal gut, saliva, and tooth/gum) to characterize temporal changes and community features associated with preterm birth. For the nine women in the validation set, 246 vaginal samples were analyzed. The researchers found that microbiota community composition remained "remarkably" stable at all four body sites […]