Special Considerations for Bacterial Vaginosis

Allergy or Intolerance to the Recommended Therapy

Clindamycin cream or oral clindamycin is preferred in case of allergy or intolerance to metronidazole. Metronidazole gel can be considered for patients who do not tolerate systemic metronidazole, but patients allergic to oral metronidazole should not be administered metronidazole vaginally.

Pregnancy

All symptomatic pregnant women should be tested and treated. BV has been associated with adverse pregnancy outcomes (e.g., premature rupture of the membranes, chorioamnionitis, preterm labor, preterm birth, postpartum endometritis, and post-cesarean wound infection).

Some specialists prefer using systemic therapy to treat possible subclinical upper genital tract infections among women at low risk for preterm delivery (i.e., those who have no history of delivering an infant before term). Existing data do not support the use of topical agents during pregnancy. Evidence from three trials suggests an increase in adverse events (e.g., prematurity and neonatal infections), particularly in newborns, after use of clindamycin cream.

Multiple studies and meta-analyses have not demonstrated a consistent association between metronidazole use during pregnancy and teratogenic or mutagenic effects in newborns.

Recommended Regimens

Metronidazole 250 mg orally three times a day for 7 days
or
Clindamycin 300 mg orally twice a day for 7 days.

Because treatment of BV in asymptomatic pregnant women at high risk for preterm delivery (i.e., those who have previously delivered a premature infant) with a recommended regimen has reduced preterm delivery in three of four randomized controlled trials, some specialists recommend the screening and treatment of these women. However, the optimal treatment regimens have not been established. The screening (if conducted) and treatment should be performed at the first prenatal visit.

The two trials that examined the use of metronidazole during pregnancy used the 250-mg regimen; the recommended regimen for BV in nonpregnant women is 500 mg twice daily. Some specialists also recommend this higher dose for treatment of pregnant women. In one published study, women with BV were treated at 19 weeks with a regimen of an initial dose of 2 g, followed by a 2-g dose 2 days later; the regimen was repeated 4 weeks later. This regimen was not effective in reducing preterm birth in any group of women.

Data are conflicting regarding whether treatment of asymptomatic pregnant women who are at low risk for preterm delivery reduces adverse outcomes of pregnancy. Several unpublished trials have evaluated screening and treatment for BV among asymptomatic low-risk pregnant women in the first or early second trimester. One trial, using oral clindamycin, demonstrated a reduction in spontaneous preterm birth; another indicated a reduction in postpartum infectious complications.

Follow-Up of Pregnant Women

Treatment of BV in asymptomatic pregnant women who are at high risk for preterm delivery might prevent adverse pregnancy outcomes. Therefore, a follow-up evaluation 1 month after completion of treatment should be considered to evaluate whether therapy was effective.

HIV Infection

Patients who have BV and also are infected with HIV should receive the same treatment regimen as those who are HIV-negative.