BV is not completely understood by scientists, and the best ways to prevent it are unknown. However, it is known that BV is associated with having a new sex partner or having multiple sex partners.
The following basic prevention steps can help reduce the risk of upsetting the natural balance of bacteria in the vagina and developing BV:
Limit the number of sex partners.
Do not douche.
Use all of the medicine prescribed for treatment of BV, even if the signs and symptoms go away.