Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age, and it is sometimes accompanied by discharge, odor, pain, itching, or burning.
The cause of BV is not fully understood. BV is associated with an imbalance in the bacteria that are normally found in a woman's vagina. The vagina normally contains mostly "good" bacteria, and fewer "harmful" bacteria. BV develops when there is a change in the environment of the vagina that causes an increase in harmful bacteria.
Scientific studies suggest that BV is common in women of reproductive age. In the United States, as many as 16% of pregnant women have BV. This varies by race and ethnicity from 6% in Asians and 9% in whites to 16% in Hispanics and 23% in African Americans. BV is generally more commonly seen in women attending STD clinics than in those attending family planning or prenatal clinics.
Women with BV often have an abnormal vaginal discharge with an unpleasant odor. Some women report a strong fish-like odor, especially after intercourse. The discharge is usually white or gray; it can be thin. Women with BV may also have burning during urination or itching around the outside of the vagina, or both. Some women with BV report no signs or symptoms at all.
A health care provider must examine the vagina for signs of BV (e.g., discharge) and perform laboratory tests on a sample of vaginal fluid to look for bacteria associated with BV.
Any woman can get BV. However, some activities or behaviors can upset the normal balance of bacteria in the vagina and put women at increased risk: Having a new sex partner or multiple sex partners Douching Using an intrauterine device (IUD) for contraception. Pregnant women are at increased risk for complications of BV.
In most cases, BV causes no complications. But there are some serious risks from BV:
Pregnant women with BV more often have babies who are born early or with low birth weight.
The bacteria that cause BV can sometimes infect the uterus (womb) and fallopian tubes (egg canals). This type of infection is called pelvic inflammatory disease (PID). PID can cause infertility or damage the fallopian tubes enough to increase the future risk of ectopic pregnancy and infertility. Ectopic pregnancy is a life-threatening condition in which a fertilized egg grows outside the uterus, usually in a fallopian tube.
BV can increase a woman's susceptibility to HIV infection if she is exposed to the virus.
Having BV increases the chances that an HIV-infected woman can pass HIV to her sex partner.
BV can increase a woman's susceptibility to other STDs, such as chlamydia and gonorrhea.
Although BV will sometimes clear up without treatment, all women with symptoms of BV should be treated to avoid such complications as PID. Treatment is especially important for pregnant women. All pregnant women, regardless of symptoms, who have ever had a premature delivery or low birth weight baby should be considered for a BV examination and be treated when necessary. All pregnant women who have symptoms of BV should be checked and treated. Male partners generally do not need to be treated. However, BV may spread between female sex partners.
BV is treatable with antimicrobial medicines prescribed by a health care provider. Two different medicines are recommended as treatment for BV: metronidazole or clindamycin. Either can be used with non-pregnant or with pregnant women, but the recommended dosages differ. Women with BV who are HIV-positive should receive the same treatment as those who are HIV-negative. BV can recur after treatment.
Some basic prevention steps can help reduce the risk of upsetting the natural balance in the vagina and developing BV:
Use condoms during sex.
Limit the number of sex partners.
Do not douche.
Use all of the medicine prescribed for treatment of BV, even if the signs and symptoms go away.