What is the recommended treatment for bacterial vaginosis (BV) during pregnancy?

Treatment of Bacterial Vaginosis in Pregnancy

For first trimester bacterial vaginosis, use clindamycin vaginal cream 2% (one full applicator intravaginally at bedtime for 7 days), and for second and third trimesters, use oral metronidazole 250 mg three times daily for 7 days. 1

First Trimester Treatment

Clindamycin vaginal cream 2% is the first-line treatment during the first trimester because oral metronidazole is contraindicated during this period due to theoretical teratogenicity concerns, although meta-analyses have not demonstrated teratogenicity in humans. 1

• Administer one full applicator (5g) intravaginally at bedtime for 7 days 1
• This minimizes systemic fetal exposure compared to oral formulations 1
• Important caveat: Clindamycin cream is oil-based and may weaken latex condoms and diaphragms 1
• Do not confuse clindamycin vaginal cream with clindamycin vaginal ovules, which are not recommended during pregnancy 1
• Avoid metronidazole gel intravaginally during first trimester - existing data do not support topical metronidazole use during pregnancy 1

Second and Third Trimester Treatment

Oral metronidazole 250 mg three times daily for 7 days becomes the preferred treatment once the patient enters the second trimester. 1, 2

Primary Regimen

• Metronidazole 250 mg orally three times daily for 7 days 1, 2
• Systemic therapy is preferred over topical therapy to treat possible subclinical upper genital tract infections, particularly in women at high risk for preterm delivery 1

Alternative Regimens

• Metronidazole 2g orally as a single dose (lower efficacy but useful for compliance concerns) 1, 2
• Clindamycin 300 mg orally twice daily for 7 days 1, 2
• Metronidazole gel 0.75% intravaginally (though systemic therapy is preferred) 1

Safety Evidence

• Meta-analyses show no association between metronidazole exposure during later trimesters and preterm birth, low birth weight, or congenital anomalies 1
• FDA classifies metronidazole as pregnancy category B 1

Critical Clinical Pitfalls

Avoid clindamycin vaginal cream in later pregnancy - three trials demonstrate increased adverse events including prematurity and neonatal infections after use of clindamycin cream, particularly affecting newborns. 1

• Patients should avoid alcohol during metronidazole treatment and for 24 hours afterward due to potential disulfiram-like reaction 2, 3
• Do not treat male sex partners - this does not influence treatment response or reduce recurrence rates 1, 2

Rationale for Treatment

Bacterial vaginosis is associated with serious adverse pregnancy outcomes that justify treatment: 1, 2

• Premature rupture of membranes
• Chorioamnionitis
• Preterm labor and preterm birth
• Postpartum endometritis
• Post-cesarean wound infection

Treatment of bacterial vaginosis in high-risk pregnant women (those with prior preterm delivery) may reduce the risk of preterm delivery. 1, 2

Follow-Up Recommendations

• Follow-up visits are generally unnecessary if symptoms resolve 1, 2
• For high-risk pregnant women, consider a follow-up evaluation one month after treatment completion to ensure successful treatment 1

Treatment Algorithm Summary

First Trimester:

• Clindamycin vaginal cream 2%, one applicator intravaginally at bedtime × 7 days 1

Second/Third Trimester:

• Metronidazole 250 mg orally three times daily × 7 days (preferred) 1, 2
• Alternative: Clindamycin 300 mg orally twice daily × 7 days 1, 2
• Alternative: Metronidazole 2g orally single dose (if compliance concern) 1, 2

All symptomatic pregnant women should be tested and treated for bacterial vaginosis regardless of risk status. 2