1 Background

Numerous studies have demonstrated that bacterial vaginosis (BV) is associated with adverse outcomes of pregnancy (AOP), especially premature delivery and delivery of a low-birthweight infant [1]. BV is also associated with pelvic inflammatory disease (PID) and complications following gynecologic procedures, and is the most common cause of vaginitis in women [2]. No single organism causes BV, rather it is characterized by a change in the microbiologic flora of the vagina. Normally, nearly 90% of the vaginal microbiologic flora [3] are Lactobacillus sp., in particular, lactobacilli that produce H 2 O 2 and lactic acid. However, women with BV have fewer lactobacilli, are more likely to have a non-H 2 O 2-producing lactobacilli [4], and have much higher quantities of Gram-negative and anaerobic bacteria, which increase 100 to 1000-fold [3]. It is thought that organisms of BV ascend from the vagina into the upper genital tract and there cause complications [1].