What is the appropriate treatment for a 34‑week pregnant woman with bacterial vaginosis and vaginal candidiasis?

Treatment of Bacterial Vaginosis and Vaginal Candidiasis at 34 Weeks Gestation

Treat both infections concurrently: oral metronidazole 500 mg twice daily for 7 days for the bacterial vaginosis AND topical clotrimazole 1% cream 5 g intravaginally for 7–14 days for the yeast infection. 1, 2, 3

Bacterial Vaginosis Treatment in Pregnancy

Why Treatment is Essential at 34 Weeks

• All symptomatic pregnant women with bacterial vaginosis must be treated because untreated BV increases the risk of preterm birth by 1.4- to 6.9-fold, premature rupture of membranes by 2.0- to 7.3-fold, and postpartum endometritis. 3
• Even at 34 weeks, treatment reduces infectious complications and provides symptom relief. 3

First-Line Regimen

• Oral metronidazole 500 mg twice daily for 7 days is the preferred treatment with approximately 95% cure rate. 1, 3
• This oral regimen is superior to intravaginal options during pregnancy and is safe at all gestational ages. 3, 4

Alternative Regimens (if oral therapy not tolerated)

• Oral clindamycin 300 mg twice daily for 7 days. 3
• Metronidazole gel 0.75% intravaginally once daily for 5 days. 3
• Clindamycin cream 2% intravaginally at bedtime for 7 days (though less preferred due to lower efficacy and potential neonatal concerns). 3

Critical Safety Warnings for BV Treatment

• The patient must avoid all alcohol during metronidazole therapy and for 24 hours after the last dose to prevent a disulfiram-like reaction (flushing, nausea, vomiting, tachycardia). 1, 3
• If clindamycin cream is used, warn that it is oil-based and will weaken latex condoms and diaphragms. 1, 3

Follow-Up Requirements

• Schedule a follow-up visit approximately one month after completing therapy to confirm microbiologic cure, as persistent BV poses ongoing pregnancy risks. 1, 3
• This follow-up is specifically recommended in pregnancy, unlike in non-pregnant women where it is unnecessary if symptoms resolve. 3

Vaginal Candidiasis Treatment in Pregnancy

Why Only Topical Azoles Are Safe

• Oral fluconazole is absolutely contraindicated at any dose during pregnancy due to teratogenic risks including spontaneous abortion, craniosynostosis, facial dysmorphisms, and cardiac malformations. 2
• Only intravaginal topical azole antifungals are considered safe and effective during pregnancy. 2

Recommended Topical Regimens (choose one)

• Clotrimazole 1% cream 5 g intravaginally for 7–14 days (preferred for pregnancy). 2
• Clotrimazole 100 mg vaginal tablet once daily for 7 days. 2
• Miconazole 2% cream 5 g intravaginally for 7 days. 2
• Terconazole 0.4% cream 5 g intravaginally for 7 days. 2

Why 7-Day Courses Are Essential

• Seven-day topical azole regimens achieve 80–90% cure rates in pregnant women, significantly more effective than shorter 1- or 3-day courses. 2, 4
• The longer duration is necessary because pregnancy-related hormonal changes make candidiasis more difficult to eradicate. 2

If Severe Vulvovaginitis Present

• If the patient has extensive erythema, edema, excoriation, or fissures, extend the topical azole regimen to 7–14 days rather than the standard 7 days. 2

Concurrent Treatment Strategy

Administering Both Medications Simultaneously

• There is no contraindication to using oral metronidazole and intravaginal clotrimazole concurrently. 2, 3
• The patient should take metronidazole 500 mg orally twice daily with food and apply clotrimazole cream intravaginally at bedtime. 2, 3
• This approach treats both infections without delay, which is important given the gestational age and proximity to delivery. 3

Partner Management

• Routine treatment of the male sexual partner is not recommended for bacterial vaginosis, as multiple randomized trials show no impact on recurrence or maternal outcomes. 3
• For candidiasis, partners should only be treated if they have symptomatic balanitis, using topical antifungals. 2

Common Pitfalls to Avoid

Medication Errors

• Do not prescribe single-dose metronidazole 2 g; it has lower efficacy than the 7-day regimen and should be avoided in pregnancy. 3
• Never prescribe oral fluconazole at any dose during pregnancy—this is a critical safety issue. 2
• Do not use boric acid suppositories, which are contraindicated during pregnancy. 2

Diagnostic Considerations

• Confirm BV diagnosis using Amsel's criteria: at least 3 of 4 findings (homogeneous white discharge, clue cells on microscopy, vaginal pH > 4.5, positive whiff test). 3
• Candidiasis typically presents with vulvar pruritus, thick white discharge, and normal vaginal pH ≤ 4.5 with yeast or pseudohyphae on wet mount. 2

Treatment Failure Management

• If BV symptoms persist after the 7-day metronidazole course, consider retreatment with the same regimen or switch to oral clindamycin 300 mg twice daily for 7 days. 3
• If candidiasis symptoms persist after topical azole therapy, suspect non-albicans Candida species (particularly C. glabrata) and extend treatment to 7–14 days with continued topical azole therapy—do not escalate to oral fluconazole. 2

Recurrence Counseling

• Bacterial vaginosis recurs in 50–80% of women within one year; counsel the patient to seek care if symptoms reappear postpartum. 3
• Recurrent vulvovaginal candidiasis (≥4 episodes per year) may require extended suppressive therapy postpartum, but this is not initiated during pregnancy. 4