Bacterial vaginosis

This is a common condition in women caused by an imbalance in the bacteria that live normally in the vagina.

What causes it

The cause of bacterial vaginosis is not known. It does not seem to be sexually transmitted, but is more common in sexually active women who have a new partner.


There may be a vaginal discharge which is usually thin and grey or white in colour or an unpleasant ‘fishy’ smell especially after sex.

Other problems it can cause

Generally there are no long-term problems with bacterial vaginosis although it may recur and therefore can be distressing.

BV can increase the risk of premature birth, women at high risk of premature birth should have a test for BV in future pregnancies.
BV has been associated with pelvic inflammatory disease (PID) in women having procedures such as termination of pregnancy or IUD insertion.

Many doctors will test for bacterial vaginosis before these procedures are performed. It may also be associated with an increased risk of HIV infection.


It is diagnosed by taking a swab from the vagina which is then examined under a microscope.


Bacterial vaginosis usually clears up without treatment. Treatment is generally only indicated for women with symptoms.

When indicated treatment is with a prescribed course of antibiotic tablets.

Alcohol should not be taken while on antibiotics or in the 48 hours after the antibiotics are stopped.


For more information contact Centre for Disease Control's Clinic 34.

Last updated: 12 May 2016

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