Bacterial vaginosis and pregnancy

What is bacterial vaginosis?

Bacterial vaginosis (also called BV or vaginitis) is an infection caused when there’s too much of certain bacteria in the vagina. It’s the most common vaginal infection in women ages 15 to 44.

BV is not a sexually transmitted infection (also called STI or sexually transmitted disease or STD), but it is common in sexually active women and it rarely happens to women who haven’t had sex. An STI is an infection you can get by have unprotected sex with an infected person. If you have BV that’s not treated, it can increase your risk of getting an STI. It’s important to have any infection treated during pregnancy to help protect you and your baby.

What causes BV?

We don’t know for sure what causes BV. Any woman can get it, but you’re at increased risk for BV if you: 

• Have new sex partners
• Have more than one sex partner
• Douche (use water or other liquid to clean inside the vagina)
• Are pregnant
• Are African-American. BV is twice as common in African-American women than in white women.
• Have an intrauterine device (also called IUD), especially if you have irregular bleeding. An IUD is a kind of birth control. It's a t-shaped piece of plastic that's placed in your uterus that helps prevents prevent pregnancy.

How can BV affect pregnancy?

The Centers for Disease Control and Prevention (also called CDC) estimates that 1 million pregnant women get BV each year. Pregnant women are at increased risk for BV because of hormone changes that happen during pregnancy. Hormones are chemicals made by the body.

If you have BV during pregnancy, your baby is at increased risk for premature birth and low birthweight. Premature birth is birth before 37 weeks of pregnancy. Low birthweight is when your baby is born weighing less than 5 pounds, 8 ounces. Being born too early or too small can cause health problems for your baby.

BV also can cause pelvic inflammatory diseases (also called PID). PID is an infection in the uterus that can increase your risk for infertility (not being able to get pregnant). 

How can you reduce your risk for BV?

Here are some things you can do to help protect yourself from BV:

• Don’t have sex. BV isn’t an STI, but you’re more likely to get it if you have sex than if you don’t. 
• Limit the number of sex partners you have. Have sex with only one person who doesn’t have other sex partners.
• Use a condom every time you have sex. Condoms are barrier methods of birth control. Barrier methods help prevent pregnancy (and STIs) by blocking or killing your partner’s sperm. Other kinds of birth control, like the pill and implants, don’t protect you from STIs.
• Don’t douche. Douching can remove normal bacteria in your vagina that can help protect you from infection.
• Use warm water only and no soap to clean the outside of your vagina. Always wipe front to back.

What are the signs and symptoms of BV?

Signs of a condition are things someone else can see or know about you, like you have a rash or you’re coughing. Symptoms are things you feel yourself that others can’t see, like having a sore throat or feeling dizzy. Many women with BV have no signs or symptoms, but you may have:

• Thin white or grey vaginal discharge
• Strong, fishy odor, especially after having sex
• Pain, itching or burning in the vagina
• Itching around the outside of the vagina
• Burning feeling when you urinate

If you think you may have BV, tell your health care provider right away. Your provider can check your vagina for signs of vaginal discharge and test a sample of vaginal fluid for bacteria associated with BV.

BV is treated with antibiotics. Antibiotics are medicines that kill infections caused by bacteria. The antibiotic may be oral (taken by mouth) or a cream or gel that you put into your vagina. Treatment with antibiotics for BV is safe for your baby during pregnancy, and it may help reduce your risk for STDs.

If you have BV:

• Take all your medicine exactly as your provider tells you to. Take all of it even if you have no signs or symptoms.
• If you have female sex partners, tell them you have BV so they can get tested and treated.
• Don’t have sex until you finish your treatment.
• Tell your provider if you have signs or symptoms after you finish your treatment.

More information

Bacterial vaginosis—CDC fact sheet

Bacterial vaginosis fact sheet from womenshealth.gov

Vaginitis FAQ from the American College of Obstetricians and Gynecologists

Last reviewed: February, 2018