Bacterial vaginosis (BV) is a common condition caused by a disruption to the balance of bacteria within the vagina. Symptoms are often mild and treatment is usually straightforward.
Due to the embarrassing nature of the symptoms – namely a fishy-smelling vaginal discharge – some women can be reluctant to seek treatment for BV. It should be stressed that BV is not unusual and not necessarily caused by promiscuity or unsafe sex.
Symptoms of bacterial vaginosis
Around half of women with bacterial vaginosis (BV) experience no symptoms whatsoever. BV doesn’t normally cause any vaginal itching or soreness. However, it can cause unusual vaginal discharge. Healthy vaginal discharge is clear or white, without a strong smell or colour. If you have bacterial vaginosis your discharge may:
- become grey or white in colour
- develop a strong fishy smell, most notably after sexual intercourse
- become particularly thin or watery
Causes of bacterial vaginosis
Bacterial vaginosis is caused by a change to the natural balance of bacteria in the vagina. The vagina contains bacteria called lactobacilli that produce lactic acid. The slight acidity of the lactic acid prevents other bacteria from growing there. Women with BV generally have a temporary shortage of lactobacilli, reducing the acidity of their vagina. Other types of bacteria are able to grow, which can result in change to vaginal discharge.
It is not fully understood why some women develop bacterial vaginosis, but you are at increased risk if you:
- are sexually active, particularly if you have a new sexual partner or multiple sexual partners
- use scented soaps, antiseptic bath liquids or bubble bath
- lean out your vagina with water or other fluids (douching)
- use vaginal deodorant
- wash your underwear with strong detergents
- use an IUD device as a contraceptive
Is bacterial vaginosis an STI?
BV is not classified as a sexually transmitted infection. However, there is uncertainty over this classification. Evidence suggests that bacterial vaginosis is more common in women with multiple sexual partners, while it is rarer in women who use a condom during sex. Some evidence suggests that women with BV can pass the condition on to female sexual partners. On the other hand there is no equivalent of BV in men (thus men can’t catch BV during sex), and BV can occur in women who aren’t sexually active. Most experts believe sexual activity is a factor in BV but not the only factor.
How dangerous is bacterial vaginosis?
The short answer is ‘not very’. As noted above, half of women experience no symptoms, and the symptoms that occur don’t cause physical discomfort. However, the abnormal vaginal discharge can be unpleasant and result in embarrassment or decreased confidence. There is also evidence that suggests BV increases the risks of contracting certain STIs.
If BV occurs during pregnancy there is a slightly increased risk of pregnancy-related complications such as miscarriage or early labour. However, the risk is small and such complications often occurred in an earlier pregnancy – they are not directly caused by BV. In the vast majority of pregnancies BV causes no problems whatsoever.
Preventing bacterial vaginosis
Since how you catch BV isn’t fully understood there is no certain way to prevent it. Ideally you should try and avoid upsetting the natural balance of bacteria in your vagina. To lower your chances of developing BV:
- Do not rinse the vagina (douching).
- Do not use bath oils, antiseptics, scented soaps, perfumed bubble bath, certain shampoos.
- Do not use vagina deodrants.
- Do not wash your underwear with strong detergents.
Getting tested for bacterial vaginosis
If you believe you have bacterial vaginosis you should visit your GP or GUM clinic for diagnosis. The doctor will listen to your symptoms and may examine your vagina. They may also take a swab from the wall of your vagina to examine for signs of BV or potential STIs. The swab only takes a few seconds and shouldn’t be painful.
Treating bacterial vaginosis
BV can be easily treated with antibiotics. The most common antibiotic treatment for BV is a course of Metronidazole tablets. Metronidazole is available as:
- a 400-500 mg tablet taken twice a day for five-to-seven days
- a single 2 gram tablet taken only once
Generally the five-to-seven day course of tablets is considered to be the most effective treatment, although your doctor will advise on which is the best option for you. Be aware that BV can often recur after treatment. Should your BV recur you should consult your GP who may prescribe a different treatment or send you to a specialist.