Bacterial Vaginosis

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What is bacterial vaginosis (BV)?
What causes BV?
What are the signs of BV?
How can I find out if I have BV?
How is BV treated?
Is it safe to treat pregnant women who have BV?
Can BV cause medical problems?
How can I prevent BV?

What is bacterial vaginosis (BV)?

Bacterial vaginosis, also called BV is the most common vaginal infection in women of childbearing age. It happens when the normal balance of bacteria in the vagina is disrupted and replaced by an overgrowth of certain bacteria. The vagina normally contains mostly “good” bacteria, and fewer “harmful” bacteria. BV develops when there is an increase in “harmful” bacteria and fewer “good” bacteria.

What causes BV?

The cause of BV is not understood. It can develop when something, like sexual contact, disrupts the balance between the good bacteria that protect the vagina from infection and the harmful bacteria that don't. It is not clear what role sexual activity plays in the development of BV, but BV is more common among women who have had vaginal sex. But BV is not always from sexual contact. We do know that certain things can upset the normal balance of bacteria in the vagina and put you more at risk for BV:

Having a new sex partner or multiple sex partners
Douching
Using an intrauterine device (IUD) for birth control
Not using a condom

We also know that you do not get BV from toilet seats, bedding, swimming pools, or from touching objects around you.

What are the signs of BV?

Women with BV may have an abnormal vaginal discharge with an unpleasant odor. Some women report a strong fish-like odor, especially after sexual intercourse. The discharge can be white (milky) or gray and thin. Other symptoms may include burning when urinating, itching around the outside of the vagina, and irritation. However, these could be symptoms of another infection too. Some women with BV have no symptoms at all.

How can I find out if I have BV?

There is a test to find out if you have BV. Your doctor takes a sample of fluid from your vagina and has it tested. Your doctor may also be able to see signs of BV, like a grayish-white discharge, during an examination of the vagina.

How is BV treated?

BV is treated with antibiotics, which are medicines prescribed by your doctor. Your doctor may give you either metronidazole or clindamycin. Generally, male sex partners of women with BV do not need to be treated. You can get BV again even after being treated.

Is it safe to treat pregnant women who have BV?

All pregnant women with symptoms of BV or who have had a premature delivery or low birth weight baby in the past should be tested for BV and treated if they have it. The same antibiotics that are used to treat non-pregnant women can be used safely during pregnancy. However, the amount of antibiotic a woman takes during pregnancy may be different from the amount taken if not pregnant.

Can BV cause medical problems?

In most cases, BV doesn't cause any problems. But some problems can happen if BV is untreated.

Pregnancy problems. BV can cause premature delivery and low birth weight babies (less than five pounds).
PID. Pelvic inflammatory disease or PID is an infection that can affect a woman's uterus, ovaries, and fallopian tubes, which carry eggs from the ovaries to the uterus. Having BV increases the risk of getting PID after a surgical procedure, such as a hysterectomy or an abortion.
Higher risk of getting other STDs. Having BV can increase the chances of getting other STDs, such as chlamydia, gonorrhea, and HIV. Women with HIV who get BV increase the chances of passing HIV to a sexual partner.

How can I prevent BV?

BV is not well understood by scientists, and the best ways to prevent it are unknown. What is known is that BV is associated with having a new sex partner or having multiple sex partners. Follow these tips to lower your risk for getting BV:

Don’t have sex. The best way to prevent any STD is to practice abstinence, or not having vaginal, oral, or anal sex.
Be faithful. Have a sexual relationship with one partner is another way to reduce your chances of getting infected. Be faithful to each other, meaning that you only have sex with each other and no one else.
Use condoms. Protect yourself with a condom EVERY time you have vaginal, anal, or oral sex. Condoms should be used for any type of sex with every partner. For vaginal sex, use a latex male condom or a female polyurethane condom. For anal sex, use a latex male condom. For oral sex, use a dental dam. A dental dam is a rubbery material that can be placed over the anus or the vagina before sexual contact.
Don't douche. Douching removes some of the normal bacteria in the vagina that protects you from infection. This may increase your chances of getting BV. It may also increase the chances of BV coming back after treatment.
Talk with your sex partner(s) about STDs and using condoms. It’s up to you to make sure you are protected. Remember, it’s YOUR body! For more information, call the Centers for Disease Control and Prevention at (800) 232-4636.
Talk frankly with your doctor or nurse and your sex partner(s) about any STDs you or your partner have or had. Talk about any discharge in the genital area. Try not to be embarrassed.
Have regular pelvic exams. Talk with your doctor about how often you need them. Many tests for STDs can be done during an exam.
If you are pregnant and have symptoms of BV or had a premature delivery or low birth weight baby in the past, get tested for BV. Get tested as soon as you think you may be pregnant.
Finish your medicine. If you have BV, finish all the medicine that you are given to treat it. Even if the symptoms go away, you still need to finish all of the medicine.

For More Information

You can find out more about bacterial vaginosis (BV) by contacting the National Women's Health Information Center at (800) 994-9662 or the following organizations.

CDC Info, HHS
Phone: (800) CDC-INFO or (800) 232-4636

CDC National Prevention Information Network (NPIN), CDC, HHS
Phone: (800) 458-5231
Internet Address: http://www.cdcnpin.org

National Center for HIV, STD and TB Prevention, CDC, HHS
Internet Address: http://www.cdc.gov/std

National Institute of Allergy and Infectious Diseases
Phone: (301) 496-5717
Internet Address: http://www.niaid.nih.gov/publications/stds.htm

American Social Health Association
Phone: (800) 783-9877
Internet Address: http://www.ashastd.org

Planned Parenthood Federation of America
Phone: (800) 230-7526
Internet Address: http://www.plannedparenthood.org

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The bacterial vaginosis FAQ was reviewed by the Division of STD Prevention, Centers for Disease Control and Prevention.

May 2005