Bacterial vaginosis, more commonly called BV, is an infection that develops in the vagina. It is the most common vaginal infection in women of reproductive age. A change in the balance of bacteria that normally live in the vagina causes BV. Factors that change the balance include douching, taking antibiotics, wearing an intrauterine device (IUD), and having unprotected sexual activity, among others.

BV is the most common vaginal condition in women ages 15 to 44. But women of any age can get it, even if they have never had sex.

You may be more at risk for BV if you:

• Have a new sex partner
• Have multiple sex partners
• Douche
• Do not use condoms or dental dams
• Are pregnant. BV is common during pregnancy. About 1 in 4 pregnant women get BV. The risk for BV is higher for pregnant women because of the hormonal changes that happen during pregnancy.
• Are African-American. BV is twice as common in African-American women as in white women.
• Have an intrauterine device (IUD), especially if you also have irregular bleeding

A change in the balance of bacteria that normally live in the vagina causes BV.

Usually, "good" bacteria (lactobacilli) outnumber "bad" bacteria (anaerobes) in your vagina. But if anaerobic bacteria become too numerous, they upset the natural balance of microorganisms in the vagina and lactobacilli decrease.

Factors that can disrupt the balance of bacteria in the vagina include:

• Reacting to antibiotics
• Using an intrauterine device (IUD)
• Having unprotected sex with one or more partners
• Douching

There are several misconceptions about the ways in which a woman can develop BV, including that she can get it by:

• Sitting on a toilet seat
• Touching and/or laying on bedding
• Swimming in a swimming pool

There is no evidence that any of these actions contributes to or causes a woman to develop BV.

The most common symptom of BV is an increased vaginal discharge that usually has a "fishy" odor. The discharge is normally a milky white or gray color. A woman may feel a burning sensation or, in rare cases, itching, when she urinates.

Sometimes a woman with BV has no symptoms. If you think you may be at risk of developing BV because you wear an intrauterine device (IUD) or because you have recently douched, taken antibiotics, or had unprotected sex, consider talking with your health care provider about getting checked for BV.

BV and vaginal yeast infections are both common causes of vaginal discharge. They have similar symptoms, so it can be hard to know if you have BV or a yeast infection. Only your doctor or nurse can tell you for sure if you have BV.

With BV, your discharge may be white or gray but may also have a fishy smell. Discharge from a yeast infection may also be white or gray but may look like cottage cheese.

If BV is untreated, possible problems may include:

• Higher risk of getting STIs, including HIV. Having BV can raise your risk of getting HIV, genital herpes, chlamydia, pelvic inflammatory disease, and gonorrhea. Women with HIV who get BV are also more likely to pass HIV to a male sexual partner.
• Pregnancy problems. BV can lead to premature birth or a low-birth-weight baby (smaller than 5 1/2 pounds at birth). All pregnant women with symptoms of BV should be tested and treated if they have it.

BV can increase the risk of acquiring certain diseases and conditions, including:

• Chlamydia, gonorrhea, herpes, HIV/AIDS, and other sexually transmitted diseases from an infected partner
• Infections following certain types of surgery, such as hysterectomy, abortion, and caesarean delivery
• Pelvic inflammatory disease

If a woman is infected with HIV and has BV, there is an increased risk of passing HIV/AIDS to her partner and possibly to her child if she is pregnant.

There is no indication that BV affects a woman's ability to get pregnant.

However, BV is associated with certain risks to the fetus, including delivering an infant preterm (before 37 weeks of pregnancy) and delivering an infant with a low birth weight (generally, 5.5 pounds or less). If you are planning a pregnancy and have recently been diagnosed with BV, you should discuss your plans with your health care provider. He or she may wish to perform a follow-up examination to ensure that you have been successfully treated before you try to get pregnant.

Diagnosis of BV requires a vaginal exam by a qualified health care provider and the laboratory testing of fluid collected from the vagina.

An examination to diagnose BV is similar to a regular gynecological checkup. While performing the examination, your health care provider will visually examine your vagina for signs of BV, which include increased vaginal discharge that has a white or gray color.

Your health care provider will also collect a small amount of your vaginal fluid with a wooden spatula or cotton-tipped applicator. The sample will be tested in a laboratory for the diagnosis of BV.

An accurate diagnosis of BV is important because it will help the provider determine whether you have BV or some other infection, such as a sexually transmitted disease like chlamydia.

To ensure an accurate diagnosis, health care providers usually ask that you:

• Do not douche for 24 hours before your exam.
• Do not use anything that might irritate your vagina, like vaginal sprays.
• Do not have sex during the 24 hours before your exam.
• Do not put anything in your vagina, including a tampon, before seeing the health care provider.
• Do not schedule your examination while you are menstruating.

Currently, the only effective treatments for BV are prescribed antibiotics, including metronidazole and clindamycin. These are prescribed as oral medications, which are taken by mouth, or as a gel or cream, both of which are inserted into the vagina with an applicator.

Even if symptoms start to disappear, it is important to complete the entire course of a prescription for BV because of the likelihood of recurrence.

Over-the-counter medications for treating vaginal problems are not effective for treating BV.

Yes, BV is usually curable with prescription antibiotics that can help readjust the balance of bacteria in the vagina. Although some over-the-counter vaginal medications are sold, these are not effective for curing BV. Currently, only prescribed antibiotics are effective.

With BV, there is a risk of relapsing if the entire course of antibiotics is not finished. Therefore, it is important to finish all of the pills in a BV prescription.

Although BV can be cured, it does carry certain risks. Women with BV are at a higher risk for:

• Delivering an infant preterm (before 37 weeks of pregnancy)
• Delivering an infant with a low birth weight (generally, 5.5 pounds or less)
• More easily contracting certain sexually transmitted diseases (STDs), including gonorrhea, herpes, and HIV/AIDS
• More easily infecting a partner with certain STDs, including HIV/AIDS
• Developing pelvic inflammatory disease

Researchers do not know exactly how BV spreads. Steps that might lower your risk of BV include:

• Keeping your vaginal bacteria balanced. Use warm water only to clean the outside of your vagina. You do not need to use soap. Even mild soap can cause irritate your vagina. Always wipe front to back from your vagina to your anus. Keep the area cool by wearing cotton or cotton-lined underpants.
• Not douching. Douching upsets the balance of good and harmful bacteria in your vagina. This may raise your risk of BV. It may also make it easier to get BV again after treatment. Doctors do not recommend douching.
• Not having sex. Researchers are still studying how women get BV. You can get BV without having sex, but BV is more common in women who have sex.
• Limiting your number of sex partners. Researchers think that your risk of getting BV goes up with the number of partners you have.

Although BV is not always transmitted sexually, the only way to avoid the sexual transmission of BV is to practice abstinence. If you decide to engage in sex, steps that will minimize your risk of developing BV include:

• Limiting the number of sexual partners that you have
• Using condoms consistently

If your partner has BV, you might be able to lower your risk by using protection during sex.

• Use a dental dam every time you have sex. A dental dam is a thin piece of latex that is placed over the vagina before oral sex.
• Cover sex toys with condoms before use. Remove the condom and replace it with a new one before sharing the toy with your partner.

To lower your risk of BV you should avoid douching. Douching removes some of the bacteria that are normally present in your vagina, which protect you from infection.

You can keep your vaginal bacteria in balance by washing your external genitalia daily with mild soap and wearing cotton or cotton-lined underpants. Avoiding tight pants and pantyhose, especially in the summer when you are perspiring more, will also lower your risk.

Any woman can get bacterial vaginosis. Having bacterial vaginosis can increase your chance of getting an STD.

What is bacterial vaginosis?

Bacterial vaginosis (BV) is a condition that happens when there is too much of certain bacteria in the vagina. This changes the normal balance of bacteria in the vagina.

How common is bacterial vaginosis?

Bacterial vaginosis is the most common vaginal condition in women ages 15-44.

How is bacterial vaginosis spread?

Researchers do not know the cause of BV or how some women get it. We do know that the condition typically occurs in sexually active women. BV is linked to an imbalance of “good” and “harmful” bacteria that are normally found in a woman’s vagina. Having a new sex partner or multiple sex partners, as well as douching, can upset the balance of bacteria in the vagina. This places a woman at increased risk for getting BV.

We also do not know how sex contributes to BV. There is no research to show that treating a sex partner affects whether or not a woman gets BV. Having BV can increase your chances of getting other STDs.

BV rarely affects women who have never had sex.

You cannot get BV from toilet seats, bedding, or swimming pools.

How can I avoid getting bacterial vaginosis?

Doctors and scientists do not completely understand how BV spreads. There are no known best ways to prevent it.

The following basic prevention steps may help lower your risk of developing BV:

• Not having sex;
• Limiting your number of sex partners;
• Not douching; and
• Using latex condoms the right way every time you have sex.

I’m pregnant. How does bacterial vaginosis affect my baby?

Pregnant women can get BV. Pregnant women with BV are more likely to have babies born premature (early) or with low birth weight than pregnant women without BV. Low birth weight means having a baby that weighs less than 5.5 pounds at birth.

Treatment is especially important for pregnant women.

How do I know if I have bacterial vaginosis?

Many women with BV do not have symptoms. If you do have symptoms, you may notice:

• A thin white or gray vaginal discharge;
• Pain, itching, or burning in the vagina;
• A strong fish-like odor, especially after sex;
• Burning when urinating;
• Itching around the outside of the vagina.

How will my doctor know if I have bacterial vaginosis?

A health care provider will examine your vagina for signs of vaginal discharge. Your provider can also perform laboratory tests on a sample of vaginal fluid to determine if BV is present.

Can bacterial vaginosis be cured?

BV will sometimes go away without treatment. But if you have symptoms of BV you should be checked and treated. It is important that you take all of the medicine prescribed to you, even if your symptoms go away. A health care provider can treat BV with antibiotics, but BV may return even after treatment. Treatment may also reduce the risk for some STDs.

Male sex partners of women diagnosed with BV generally do not need to be treated. BV may be transferred between female sex partners.

What happens if I don’t get treated?

BV can cause some serious health risks, including:

• Increasing your chance of getting HIV if you have sex with someone who is infected with HIV;
• If you are HIV positive, increasing your chance of passing HIV to your sex partner;
• Making it more likely that you will deliver your baby too early if you have BV while pregnant;
• Increasing your chance of getting other STDs, such as chlamydia and gonorrhea. These bacteria can sometimes cause pelvic inflammatory disease (PID), which can make it difficult or impossible for you to have children.