How can bacterial vaginosis causes preterm labor? if once it happened and treated for next pregnancy,what is the chance of repeat preterm labor?

B.V. and early labor: Bacterial vaginitis residing and multiplying in the vagina came cause white blood cell mobilization, irritation to the vagina, and effusion through leaking amniotic membranes into the uterus causing internal infection with resulting premature labor. Once it is treated effectively it is not a problem so have your OB assess the vaginal area regularly during your next pregnancy to eliminate B.V.