Bacterial vaginosis (BV) is the commonest cause of abnormal vaginal discharge in women of childbearing age, with a prevalence varying from 5% to 50%. It was found in 12% of pregnant women attending an antenatal clinic in the United Kingdom [1], and in 30% in women undergoing termination of pregnancy [2].

Pathophysiology

The pH of the normal vagina is preserved below 4.5. BV generally occurs as a consequence of a disturbance in the vaginal flora resulting in an increase in the pH to 6.0. This is associated with overgrowth of Gardnerella vaginalis and the other anaerobic species (up to a thousandfold), together with a reduction in lactobacilli.

Clinical features

The characteristic symptom of this condition is an offensive vaginal discharge, due to the production of amines such as putrescine, cadaverine, and trimethylamine that give off a characteristic fishy odour [3]. Vaginal inflammation is uncommon; hence, the term vaginosis is used rather than vaginitis. Symptoms may be exacerbated by factors which lead to an increase in vaginal pH such as douching, menstruation, and the presence of semen in the vagina. Although BV occurs more commonly in sexually active women, evidence for its sexual transmission is lacking, and treatment of the sexual partners of women with this condition does not prevent it from recurring [4,5]