Bacterial vaginosis is caused by bacteria, including Gardnerella, Mycoplasma and Anaerobic bacteria. The main symptom is a fishy or foul-smelling thin homogeneous grayish white discharge from the vagina. Itching is uncommon.
Bacterial vaginosis is prevalent in 15 to 25% of the female population between ages 15 and 44. In one American study, 16% of pregnant women had bacterial vaginosis. If a mother has vaginosis, the chance of delivering a baby of less than normal weight rises by 40%, and the infection causes 6% of the premature deliveries in the USA. Treating the infection with antibiotics reduced the rate of premature deliveries in certain groups of women by 35%.