Bacterial Vaginosis Test

Bacterial vaginosis (BV) is a bacterial infection in the vagina. A healthy vagina contains a balance of both 'good' (healthy) and 'harmful' (unhealthy) bacteria. Normally, the good bacteria keep the harmful type under control.

A BV infection happens when the normal balance is upset and more harmful bacteria grow than good bacteria. A BV test checks a sample of vaginal discharge (fluid that comes out of the vagina) to look for harmful bacteria. Any woman can get BV, even women who have never had sex.

But it's most common in women who are sexually active. Sometimes a BV infection doesn't cause symptoms, and it can go away on its own. But serious health problems are linked to untreated BV.

If you have symptoms, testing and treatment can help avoid the increased risk of these problems: Getting a sexually transmitted disease (STD). BV makes your vagina more acidic than normal, which increases your chance of getting STDs, such as chlamydia, genital herpes, gonorrhea, or HIV. And if you have HIV and BV, you're more likely to pass HIV to your sex partner.; Preterm birth.

If you have a BV infection during pregnancy, it can increase the chance that your baby will be born too early (premature baby) or have a low birth weight (less than 5 and a half pounds). Low birth weight can cause serious health problems for your baby, including difficulty breathing, gaining weight, and fighting infections.; There are different ways to check a sample of vaginal discharge for signs of BV: Using a microscope. This is called a 'vaginal smear' or a 'wet mount.' The sample is prepared on a glass slide and checked under a microscope for bacteria, white blood cells, and other cells that are signs of infection.; Checking for odor.

This is called a 'whiff test.' The sample is mixed with a chemical to see if it makes a strong, fishy odor, which is a sign of BV.; Testing vaginal pH. This test checks the acidity of the sample. High acidity is a sign of BV.

But a pH test alone can't diagnose BV, so it's used with other tests.; PCR test. This test checks your sample for genetic material from harmful bacteria. It's not used as much as the other three tests, because it's more expensive.;

Why this test is done

You may need testing if you have symptoms of BV. These include:

• An unusual vaginal discharge that can be gray or white. It may also be foamy or watery.
• A strong, fish-like odor, especially after sex
• Pain and/or itching in the vagina
• Itching around the outside of the vagina
• Burning feeling when urinating (peeing)

You may also need a test if you have a female sex partner who has BV or symptoms that could be BV.

How to prepare

Follow the instructions your provider gives you to prepare for this test. For 24 hours before your test, you'll usually need to avoid:

• Using tampons
• Douching (rinsing the vagina with water or other fluid)
• Using creams or medicines in the vagina
• Having vaginal sex

Other names for this test

vaginal pH test, KOH test, wet mount test