In a pregnant patient with suspected bacterial vaginosis, which treatment is most appropriate?

• A. Oral metronidazole
• B. Metronidazole gel 0.75% once daily for 5 days
• C. Clindamycin vaginal cream
• D. No treatment

Answer: (B)

Treating suspected BV in pregnancy aims to clear the infection while minimizing fetal exposure, since BV in pregnancy is linked to adverse outcomes if not addressed. Using metronidazole as a vaginal gel delivers the active drug directly to the vagina with much less systemic absorption than oral therapy. This local approach is effective and has a favorable safety profile for both mother and fetus, making it a preferred first-line option in pregnancy. The 0.75% gel given once daily for 5 days is a standard, well-tolerated regimen that matches the cure rates of oral therapy while reducing systemic exposure.

Oral metronidazole would also treat BV but involves more systemic exposure, which is why the vaginal gel is often favored in pregnancy. Clindamycin vaginal cream is an alternative, but guidelines typically prioritize metronidazole first-line in this setting. Doing nothing is not appropriate, as treatment reduces risks to the pregnancy associated with BV. Remember to avoid alcohol during metronidazole treatment and for 24 hours after finishing.