Bacterial Vaginosis in Pregnancy

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The vagina naturally has bacteria in it. These bacteria live, causing no problems, for long periods of time. When the environment is disrupted, there can be an overgrowth of this bacteria. The things that can interfere with normal growth can include medications including antibiotics, spermicides, douching, infections, having sex and others.

Symptoms of Bacterial Vaginosis

Typically you would suspect bacterial vaginosis (BV), also known as vaginitis, if you had an increase in discharge.

While it can be normal in pregnancy to notice an increased discharge, the discharge you would have with bacterial vaginosis is different. This is more likely to a thin discharge that is dark, gray or even green tinged. There is usually a fish odor noted as well. You may also find that the smell is more common after you have had sex recently. Itching might occur if you have lots of discharge from the vagina, but it is not a common symptom of bacterial vaginosis.

You should not attempt to treat the symptoms yourself. It is important, even if you think you know what is causing the symptoms, to talk to your doctor or midwife. There are some types of infections that can cause preterm labor. Misdiagnosing yourself could put you and your baby at risk.

About 50% of women will not have symptoms of bacterial vaginosis. Though it can occur commonly in pregnancy. It may also lead to preterm labor, which is why you will also be tested for bacterial vaginosis should you have signs of premature labor.

Bacterial vaginosis is something that reoccurs often. The more often it happens, the more likely that you are to have a sexually transmitted infections (STI). Though your doctor or midwife may have already screened you for this possibility, you may need multiple screenings.

If you also have inflammation it is called vaginitis.

This may or may not change the diagnosis. Only your practitioner can tell you and help you treat it effectively.

How do you treat bacterial vaginosis?

Your treatment may consist of a vaginal gel or cream or perhaps an oral medication. Typically used medications include clindamycin and metronidazole. Side effects may include nausea and vomiting. Which treatment your doctor or midwife choose will be based on your symptoms and your pregnancy status. Be sure to complete your treatment and talk to your practitioner if you have additional or persistant symptoms.


American College of Obstetricians and Gynecologists (ACOG). Patient Education Pamphlet: Vaginitis: Causes and Treatments. August 2011.

Bacterial Vaginosis. March of Dimes.

Donders GG, Van Calsteren K, Bellen G, Reybrouck R, Van den Bosch T, Riphagen I, Van Lierde S. Predictive value for preterm birth of abnormal vaginal flora, bacterial vaginosis and aerobic vaginitis during the first trimester of pregnancy. BJOG. 2009 Sep;116(10):1315-24. doi: 10.1111/j.1471-0528.2009.02237.x. Epub 2009 Jun 17.

Tolosa JE, Chaithongwongwatthana S, Daly S, et al. The International Infections in Pregnancy (IIP) study: variations in the prevalence of bacterial vaginosis and distribution of morphotypes in vaginal smears among pregnant women. Am J Obstet Gynecol 2006; 195:1198.

van Schalkwyk J, Yudin MH; Infectious Disease Committee, Yudin MH, Allen V, Bouchard C, Boucher M, Boucoiran I, Caddy S, Castillo E, Kennedy VL, Money DM, Murphy K, Ogilvie G, Paquet C, van Schalkwy JK; Vulvovaginitis: screening for and management of trichomoniasis, vulvovaginal candidiasis, and bacterial vaginosis. Society of Obstetricians and Gynaecologists of Canada. J Obstet Gynaecol Can. 2015 Mar;37(3):266-76.

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