S1-Guideline on Bacterial Vaginosis in Gynecology and Obstetrics: Long version - AWMF Guideline, registration no. 015/028, July 2013 Langfassung - AWMF-Register Nr. 015/028, Juli 2013.

Normal vaginal flora of sexually mature women consists of lactobacilli, transient or commensal anaerobic and aerobic bacteria, and Candida species from skin and gut flora. The normal pH value of vaginal flora is 3.8–4.4. Lactobacilli predominate in the vaginal flora, primarily L. crispatus, L. gasseri, L. iners and L. jensenii, depending on ethnicity. Normal pH values differ significantly between ethnicities, ranging from 3.8 to 5.2. Some healthy women have no lactobacilli in their vaginal flora; the percentage of women with lactobacilli differs depending on ethnicity; the percentage for Caucasian women is around 9%, for Hispanic and African women the percentage is more than 30% with normal pH values of around 5 [14,43]. At present, there are no studies into this issue for Europe. Bacterial vaginosis (BV) is the most common microbiological disorder of the vaginal flora in sexually mature women. The prevalence of BV differs, depending on ethnicity; it is 2.4 times more common in women of African descent [13]. In Europe, the prevalence ranges from 5% in women who come for regular gynecological check-ups tomore than 30% in women treated in clinics for sexually transmitted diseases. The reported prevalence in pregnant women is between 7 and 22% [3,9,15, 22,25]. Psychosocial stress is a significant risk factor for BV [39]. There are also indications of gene–environment interactions as additional risk factors and of gene polymorphisms affecting genetic control of the individualʼs immune response to BV [35]. The abnormal oral conditions of periodontal disease have been found to be significantly correlated with disturbed vaginal flora in BV [46]. Vitamin D deficiency was identified as a risk factor for BV in pregnant women [13]. Microarray technology has been used to detect microorganisms associated with BV; in addition