Bacterial Vaginosis (BV)

What is bacterial vaginosis?

In a healthy vagina it is normal to have different bacterial types in a healthy balance. ^1,3 Lactobacilli normally dominate, keeping other bacterial species in check, including anaerobic bacteria. However, if your vaginal flora is disturbed, the anaerobic bacteria can sometimes grow out of control and cause BV. ^1,2

BV is not an STI.¹ However, sexual activity can increase your risk of developing the infection, as it can disrupt the balance of your vaginal flora.^1,6 As a result, BV is more common in people of reproductive age.² In addition, a woman can pass on BV to another woman during sex.⁷

Bacterial vaginosis symptoms

Many people with BV (~50%) don’t show any symptoms at all.^5,7 However, for those that do, the symptoms of bacterial vaginosis include:^1–4

• Unusual vaginal discharge that may be off-white, grey, thin or watery
• Discharge that has a strong fishy smell, especially after sex and during periods
• Itching or irritation around the vagina
• Burning when you pee

Bacterial vaginosis causes and risk factors

Your vaginal flora can be disturbed by anything that changes the natural chemistry of your vagina.¹ As a result, certain activities can lead to BV, such as:^1,3,5,6,8

• Being sexually active
• Having unprotected sex
• Douching (cleaning out the vagina with water or other fluids)
• Having a new sexual partner or multiple sexual partners
• Having concurrent STIs
• Smoking
• Using perfumed products around your vagina
• Washing your underwear with strong detergents
• Receiving oral sex
• Having an intrauterine device (IUD)

Importantly, you cannot get BV from hot tubs, swimming pools or toilet seats.¹

How is bacterial vaginosis diagnosed?

If you think you have BV, you should contact your GP.⁴ At your appointment, they will ask you about your medical history—including previous vaginal infections and STIs—and sexual history.^1,2,9

They will then perform a pelvic exam to assess your vagina for signs of infection.^1,4,9 This will involve an internal examination, which may be enough to indicate a diagnosis of BV.^1,4,9 However, if you tend to have vaginal discharge a lot, regardless of whether you have an infection, they may use a swab to collect a sample of your discharge.^1,4,9

 Your sample will be sent to a lab to test for “clue cells” (vaginal cells covered in bacteria) assess your vaginal pH (how acidic your discharge is).^1,2,9 A higher pH can also indicate BV.¹

If you have your period and BV, you should schedule your appointment for a day when you are no longer bleeding.⁹ This is because blood can make it difficult for your doctor to inspect your vaginal discharge.⁹

Once you have had a diagnosis, you may not need to be examined every time you think you have BV if your symptoms are typical and consistent with previous episodes. If, however, you are frequently getting recurring episodes you may need a further examination to investigate the cause of these.

How can bacterial vaginosis be treated?

Approximately 30% of cases of BV go away on their own without any treatment.^1,6 Additionally, treatment isn’t necessary if you have BV without any symptoms.

If you do have symptoms, these are usually treated with antibiotics for bacterial vaginosis:^1,7,6,9,10

• Metronidazole – available either as a single tablet, a course of tablets spread over seven days or as a gel to be inserted into your vagina once a day for five days. Avoid alcohol while using metronidazole and for 24 hours afterwards, as alcohol can interact with the medication and lead to nausea and stomach pain
• Clindamycin – available as a cream to be inserted into your vagina, once daily at night, usually for seven consecutive nights. The cream or gel can weaken latex condoms and cause them to break. So, unless you are using another form of contraception, you should avoid sex for at least three days after using clindamycin

If used correctly for the appropriate length of time, these drugs for BV are known to be extremely effective.⁶ They are also approved for use in pregnant people.⁶ However, if you stop treatment early, BV may come back.⁹

Recurring bacterial vaginosis

10-15% of individuals do not improve after their first course of antibiotics and require an additional course of antibiotics.^6,7

However, BV that keeps coming back is known as recurrent bacterial vaginosis.^7,9 This is common, affecting as many as 80% of individuals within nine months of treatment.⁶

For recurrent BV, the NHS recommends using an antibiotic gel in your vagina for a few months.⁷ Your GP will recommend how long you should continue treatment for and may also want to identify whether there is a specific trigger for your BV, such as sexual activity or your period.⁷

How to prevent BV

Anyone who has or has had BV will be pleased to know there are plenty of things you can do to relieve the symptoms and prevent BV from returning:^1,6

• Wash your genital area with water and plain soap
• Have showers instead of baths
• Avoid using perfumed products around your vagina
• Avoid douching
• Avoid using strong detergents to wash your underwear
• Quit smoking
• Avoid allowing anything that has touched your anus to touch your vagina
• Limit your number of sexual partners
• Wear cotton underwear

Bacterial vaginosis and pregnancy

BV is relatively common in pregnancy, affecting around 25% of pregnant people, due to the hormonal changes that occur.¹ However, some research has indicated that there is a link between BV if left untreated and complications during pregnancy, such as:⁶

• Premature birth
• Miscarriage
• Low birth weight

Importantly, no causal relationship between BV and these potential problems during pregnancy has yet been established.³ Furthermore, other research has indicated that these problems may have alternative causes.³

However, if you are pregnant and develop BV, you should see your GP, as they can recommend the best treatment for you.

Sources

1. https://my.clevelandclinic.org/health/diseases/3963-bacterial-vaginosis
2. https://www.who.int/news-room/fact-sheets/detail/bacterial-vaginosis
3. https://www.mayoclinic.org/diseases-conditions/bacterial-vaginosis/symptoms-causes/syc-20352279
4. https://www.nhsinform.scot/illnesses-and-conditions/sexual-and-reproductive/bacterial-vaginosis/
5. https://cks.nice.org.uk/topics/bacterial-vaginosis/
6. https://www.ncbi.nlm.nih.gov/books/NBK459216/
7. https://www.nhs.uk/conditions/bacterial-vaginosis/
8. https://womenshealth.gov/a-z-topics/douching
9. https://www.mayoclinic.org/diseases-conditions/bacterial-vaginosis/diagnosis-treatment/drc-20352285
10. https://www.rwt.nhs.uk/PIL/MI_12282014_13.09.23_V_1.pdf