In most women, BV causes no harm whatsoever, though the discharge may be unpleasant. However, if you have untreated BV during pregnancy, there is a slightly higher risk of premature labour, miscarriage, preterm birth and having a baby with a low birthweight. If you are pregnant and suspect you may have BV, you should see your GP or midwife. BV can also cause complications if you have had recent gynaecological surgery- the chance of developing an infection of the womb is higher.

There is also some evidence that women with untreated BV may be at an increased risk of getting other STIs and Pelvic Inflammatory Disease (PID).