1. Health

Bacterial Vaginosis and Risk of Miscarriage


Updated June 11, 2014

You probably already know that bacteria are always present in your body and that many of these bacteria serve an important purpose in health. Sometimes, however, harmful bacteria can lead to infection. Bacterial vaginosis is a condition in which the normal balance of bacteria in the vagina is disturbed, leading to an overgrowth of bothersome species that overpowers the usual beneficial species.


The condition can cause thin white or gray discharge from the vagina with an unpleasant, potentially fish-like odor. Some women have burning during urination or genital itching. Other women can have bacterial vaginosis with no obvious symptoms.

Bacterial vaginosis is not the same as having a yeast infection. A yeast infection can cause itching but is more likely to cause a thick, white discharge. Yeast infections are caused by fungi, however, rather than bacteria. Yeast infections have not been associated with risk of miscarriage.

Incidence of Bacterial Vaginosis:

Bacterial vaginosis is very common. A 2007 study found that almost a third of women in a population survey were positive for bacterial vaginosis. The condition was more likely in women who douched and in certain ethnic groups.


The usual treatment of bacterial vaginosis is antibiotics to kill the invading bacterial species. Some researchers believe that applying yogurt to the vagina might also work as a treatment. Because the live bacteria in yogurt are similar to the bacteria that naturally inhabit the vagina, the idea is that applying yogurt may restore the natural bacterial balances. (But obviously, if you suspect that you have bacterial vaginosis, you should consult your doctor before taking any action.)

Risks of Bacterial Vaginosis During Pregnancy:

The relationship between bacterial vaginosis and miscarriage has been the subject of a lot of research in recent years. Studies have found various types of links between bacterial vaginosis and problems with pregnancy. Some studies have found that having a bacterial vaginosis infection increases the risk of having a low-birthweight infant or giving birth prematurely.

In terms of miscarriage, numerous studies have found a link between bacterial vaginosis and second-trimester miscarriage (the condition does not appear to cause first-trimester miscarriage). Some doctors are starting to call for routine screenings of patients considered at high risk, but right now there are no recommendations to universally screen pregnant women for this condition.

If you have any suspicion that you may have bacterial vaginosis, be sure to mention this to your doctor.


Allsworth, Jenifer E. and Jeffrey F. Peipert, "Prevalence of Bacterial Vaginosis." Obstetrics & Gynecology 2007. Accessed 12 Mar 2008.

Center for Disease Control, "STD Facts - Bacterial Vaginosis (BV)." 22 Feb 2008. Accessed 12 Mar 2008.

Llahi-Camp, J.M., R. Rai, C. Ison, L. Regan, and D. Taylor-Robinson, "Association of bacterial vaginosis with a history of second trimester miscarriage." Human Reproduction 1996. Accessed 12 Mar 2008.

Oakeshott, Pippa, Phillip Hay, Sima Hay, Frances Steinke, Elizabeth Rink, and Sally Kerry, "Association between bacterial vaginosis or chlamydial infection and miscarriage before 16 weeks' gestation: prospective community based cohort study. BMJ 2002. Accessed 12 Mar 2008.

Svare, J.A., H. Schmidt, B.B. Hansen, and G. Lose, "Bacterial vaginosis in a cohort of Danish pregnant women: prevalence and relationship with preterm delivery, low birthweight and perinatal infections." BJOG Dec 2006. Accessed 12 Mar 2008.

Van Kessel, K., N. Asserfi, J. Marrazzo, and L. Eckert, "Common complementary and alternative therapies for yeast vaginitis and bacterial vaginosis: a systematic review." Obstetrics and Gynecology Survey May 2003. Accessed 12 Mar 2008.

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