What is the recommended treatment for a vaginal yeast infection in an 18-week pregnant woman?

Treatment of Vaginal Yeast Infection at 18 Weeks Pregnancy

Use a 7-day course of topical azole antifungals—specifically clotrimazole, miconazole, or terconazole intravaginally—as this is the only safe and effective treatment for vaginal yeast infections during pregnancy. 1

First-Line Treatment Regimens

The CDC recommends the following intravaginal options for pregnant women, all administered for 7 days 1:

• Clotrimazole 1% cream 5g intravaginally for 7-14 days 1
• Clotrimazole 100mg vaginal tablet daily for 7 days 1
• Miconazole 2% cream 5g intravaginally for 7 days 1
• Miconazole 100mg vaginal suppository daily for 7 days 1
• Terconazole 0.4% cream 5g intravaginally for 7 days 1

Critical Management Points

Oral fluconazole is absolutely contraindicated during pregnancy due to dose-dependent teratogenic effects, despite being first-line therapy in non-pregnant women. 2, 3 While some sources suggest fluconazole may be safe at lower doses (150mg), the safest approach is to avoid it entirely during pregnancy. 3

Seven-day regimens are more effective than shorter courses during pregnancy, with cure rates of 78-87% depending on trimester. 1, 4 The longer duration is necessary because pregnancy creates a favorable environment for Candida growth, making infections more difficult to eradicate. 5

Diagnostic Confirmation

Before treating, confirm the diagnosis with 1:

• Clinical symptoms: pruritus, white discharge, vulvar erythema
• Vaginal pH ≤4.5 (normal pH rules out bacterial vaginosis)
• Wet mount with 10% KOH showing yeasts or pseudohyphae, or positive culture

Do not treat asymptomatic colonization, as 20-30% of pregnant women harbor Candida without infection. 6 Treatment is only indicated when symptoms are present. 1

Why Topical Therapy Only in Pregnancy

Topical azoles have been extensively studied in pregnancy with excellent safety profiles 3, 5:

• Minimal systemic absorption when applied intravaginally
• No teratogenic effects demonstrated in multiple studies
• Clotrimazole in first trimester actually reduces premature birth rates 6
• Miconazole achieves comparable cure rates in pregnant and non-pregnant women 5

Partner Management

Do not treat sexual partners, as vulvovaginal candidiasis is not sexually transmitted. 1, 2 The only exception is if the male partner has symptomatic balanitis, in which case topical antifungal treatment may be beneficial. 1

Follow-Up Considerations

Patients should return only if symptoms persist or recur, as routine follow-up is unnecessary when symptoms resolve. 1, 2 Recurrence is common in pregnancy due to elevated estrogen levels creating favorable conditions for Candida overgrowth. 6

Common Pitfalls to Avoid

• Do not use single-dose or 3-day regimens that are effective in non-pregnant women—pregnancy requires 7-day courses 1
• Avoid nystatin as first-line therapy, as topical azoles are significantly more effective (80-90% cure rates vs lower efficacy with nystatin) 7, 5
• Remember that oil-based creams and suppositories weaken latex condoms and diaphragms 2
• Do not prescribe oral antifungals regardless of severity—topical therapy is the only appropriate option 1