Bacterial vaginosis and risk of miscarriage

The presence of bacterial vaginosis or BV during the first trimester of pregnancy doubles the likelihood of a miscarriage by the end of the second trimester. BV (vaginal inflammation caused by the bacterium Gardnerella vaginalis) is known to increase the chances of preterm delivery. To investigate any miscarriage risk, American researchers followed 1916 women, all in their first trimester of pregnancy, at an average of 10 weeks' gestation. They were screened for BV and 40 percent (757 women) had a positive result.  Women with the highest level of vaginal bacteria were 2.5 times more likely to have a pregnancy loss by 20 weeks' gestation than those with the lowest levels. This means that in addition to preterm birth, high levels of BV are also related to risk of miscarriage among women without a history of multiple miscarriages. Doctors don't routinely screen for BV in pregnancy among low-risk women because oral treatment does not seem to be effective for reducing the risk of preterm delivery. The findings suggest that it could be beneficial to screen for BV in the first trimester and treat it to reduce the risk of miscarriage, particularly since early treatment for BV may reduce the subsequent inflammation, which may be the true risk factors for increased preterm delivery and/or miscarriage among pregnant women with BV.