What medications are recommended for STD prophylaxis in pregnancy?

STD Prophylaxis Medications During Pregnancy

For STD prophylaxis in pregnancy, azithromycin (1g oral single dose) is the first-line treatment for chlamydial infections, while ceftriaxone (250mg IM single dose) is recommended for gonococcal infections. These medications provide the best balance of efficacy and safety for pregnant women requiring STD prophylaxis 1.

First-Line Medications by Infection Type

Chlamydial Infections

• First choice: Azithromycin 1g orally as a single dose 1
  • High compliance rate due to single-dose regimen
  • Demonstrated safety in pregnancy
  • Proven efficacy against chlamydial infections
• Alternatives (if azithromycin cannot be tolerated):
  • Amoxicillin 500mg orally three times daily for 7 days 2, 1
  • Erythromycin base 500mg orally four times daily for 7 days 2

Gonococcal Infections

• First choice: Ceftriaxone 250mg IM as a single dose 2, 1
  • Also covers potential co-infection with chlamydia
• Alternatives:
  • Cefixime 400mg orally as a single dose 2, 3
  • Spectinomycin 2g IM as a single dose (if available) 2

Bacterial Vaginosis

• Recommended regimen: Metronidazole 500mg orally twice daily for 7 days 2, 3
• Alternative: Clindamycin 300mg orally twice daily for 7 days 2

Trichomoniasis

• Recommended regimen: Metronidazole 500mg orally twice daily for 7 days 2, 3
  • Earlier concerns about teratogenesis have not been confirmed by recent data

Important Contraindications in Pregnancy

Several antibiotics commonly used for STD treatment in non-pregnant patients must be avoided during pregnancy:

• Doxycycline: Contraindicated due to risk of dental staining and inhibition of bone growth in the fetus 2, 1
• Fluoroquinolones (ciprofloxacin, levofloxacin): Contraindicated due to potential fetal harm 1, 3
• Erythromycin estolate: Contraindicated due to risk of maternal hepatotoxicity 2
• Tetracyclines: Contraindicated due to risk of dental staining and bone growth inhibition 1, 4

Screening Recommendations

• All pregnant women should be screened for:
  • Syphilis: Early in pregnancy with serologic titers repeated in third trimester 1
  • Chlamydia: Especially women <25 years of age or those with new/multiple partners 1
  • Gonorrhea: For women at risk or in high-prevalence areas 5
  • HIV: As early as possible in pregnancy 5

Follow-up and Partner Treatment

• Test of cure is recommended 3 weeks after treatment completion for pregnant women, preferably by nucleic acid amplification test (NAAT) 1
• Patients should abstain from sexual intercourse until both they and their partners have completed treatment 1
• Partner treatment is essential to prevent reinfection 1, 3

Clinical Pearls and Pitfalls

• Pearl: Every diagnosis of an STD warrants full screening for concomitant genital infections 1, 3
• Pitfall: Neonatal ocular prophylaxis does not prevent perinatal transmission of chlamydia 2
• Pearl: Physiological changes in pregnancy (increased glomerular filtration rate, increased total body volume) may affect antibiotic pharmacokinetics 4
• Pitfall: Assuming that all antibiotics safe in non-pregnant patients are safe during pregnancy
• Pearl: Treatment of sex partners is critical to prevent reinfection, which is particularly important during pregnancy 1, 3

By following these evidence-based recommendations for STD prophylaxis in pregnancy, clinicians can effectively treat infections while minimizing risks to both mother and fetus.