Bacterial vaginosis is caused by a change in the natural balance of bacteria in your vagina. Many bacteria normally reside in the vagina. One type, called lactobacilli, maintains the normal acidity of the vagina. By doing so, lactobacilli helps keep the lining of the vagina healthy and prevent the growth of certain bacteria that cause infections. Bacterial vaginosis, the most common vaginal infection, results when the number of protective lactobacilli decreases and the number of other bacteria that are normally present (such as Gardnerella vaginalis and Peptostreptococcus bacteria) increases.
What causes this to happen is not fully understood, but what is known is that bacterial vaginosis is more common among women who have or do the following:
Are sexually active (but women who have not had sex can also get bacterial vaginosis)
Have a sexually transmitted infection
Having multiple sexual partners: BV is more common in people who have multiple sexual partners.
Douching: Douching (using a liquid to clean the inside of the vagina) can disrupt the balance of bacteria in the vagina and increase the risk of BV.
Using certain types of birth control: Using an intrauterine device (IUD) or condoms lubricated with nonoxynol-9 may increase the risk of BV.
Having a weakened immune system: People with HIV or other conditions that weaken the immune system may be more susceptible to BV.
Using scented hygiene products: Using scented soaps, douches, or other hygiene products can disrupt the normal balance of bacteria in the vagina and increase the risk of BV.
Bacterial vaginosis in pregnancy
If you develop bacterial vaginosis in pregnancy, there’s a small chance of complications, such as premature birth or miscarriage. But bacterial vaginosis causes no problems in the majority of pregnancies.
It is important to note that BV is not a sexually transmitted infection (STI). However, having multiple sexual partners or engaging in certain sexual practices (such as unprotected sex) may increase the risk of developing BV. A woman can pass it to another woman during sex and you’re more likely to get an STI if you have bacterial vaginosis. This may be because it makes your vagina less acidic and reduces your natural defences against infection.
If you are concerned about your risk of BV or are experiencing symptoms, it is important to speak with a healthcare professional. They can help determine the cause of your symptoms and recommend appropriate treatment options.