What is the treatment for Trichomonas vaginalis and bacterial vaginosis (Bacterial Vaginosis) in pregnancy?

Treatment of Trichomonas Vaginalis and Bacterial Vaginosis in Pregnancy

For bacterial vaginosis in pregnancy, clindamycin cream 2% applied intravaginally at bedtime for 7 days is the preferred treatment during the first trimester, while metronidazole can be safely used after the first trimester. For trichomoniasis, oral metronidazole is the treatment of choice after the first trimester, but is contraindicated during the first trimester. 1, 2

Bacterial Vaginosis Treatment in Pregnancy

First Trimester:

• First-line treatment: Clindamycin cream 2% (one full applicator/5g intravaginally at bedtime for 7 days) 1
• Alternative option: Amoxicillin-clavulanic acid 1
• Metronidazole is contraindicated during the first trimester due to potential risks to fetal organogenesis 1, 2

Second and Third Trimesters:

• First-line options:
  • Metronidazole 500 mg orally twice daily for 7 days (95% cure rate)
  • Metronidazole gel 0.75%, one full applicator (5g) intravaginally once daily for 5 days
  • Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days 1

Important Considerations:

• Treatment is strongly recommended during pregnancy due to associations with:
  • Premature rupture of membranes
  • Preterm labor and birth
  • Postpartum endometritis
  • Chorioamnionitis 1
• Follow-up evaluation 1 month after treatment completion is recommended for pregnant women 1
• Patients using metronidazole should avoid alcohol during treatment and for 24 hours afterward to prevent disulfiram-like reactions 1

Trichomonas Vaginalis Treatment in Pregnancy

First Trimester:

• Metronidazole is contraindicated during the first trimester 2
• Limited options exist for first-trimester treatment:
  • Clotrimazole vaginal suppositories may be considered as an initial treatment with approximately 50% cure rate 3
  • Note that this is not ideal but may provide symptomatic relief until the second trimester when metronidazole can be used

Second and Third Trimesters:

• First-line treatment: Oral metronidazole 500 mg twice daily for 7 days 4, 5
  • Alternative: Metronidazole 2g as a single oral dose (though 7-day regimen has shown better efficacy) 5
• Treatment is warranted for the prevention of preterm birth 4

Important Considerations:

• Trichomoniasis is a sexually transmitted infection; partners should be treated simultaneously to prevent reinfection 6
• Test of cure following treatment is not recommended 4
• Metronidazole crosses the placental barrier rapidly 2

Precautions with Metronidazole Use

• Avoid alcohol during treatment and for 24 hours afterward 1
• Common side effects include:
  • Gastrointestinal disturbances
  • Metallic taste
  • Nausea (reported in 23% of patients) 1, 5
• Metronidazole is secreted in human milk in concentrations similar to those found in plasma 2

Follow-up Recommendations

• For bacterial vaginosis: Follow-up evaluation 1 month after treatment completion is recommended for pregnant women 1
• For trichomoniasis: Test of cure is not routinely recommended 4
• Recurrence of BV is common (50-80% within a year), so monitoring for symptom recurrence is important 1

Common Pitfalls to Avoid

• Failing to treat partners in cases of trichomoniasis, which can lead to reinfection 6
• Using metronidazole in the first trimester of pregnancy 2
• Not completing the full course of treatment, which may lead to treatment failure
• Not considering the high recurrence rate of bacterial vaginosis
• Failing to screen and treat high-risk asymptomatic pregnant women (those with history of previous preterm birth) for BV 1