What is the recommended treatment for Chlamydia trachomatis infection in a pregnant woman (any trimester)?

Treatment for Chlamydia in Pregnancy

First-Line Treatment

Azithromycin 1 g orally as a single dose is the definitive first-line treatment for Chlamydia trachomatis infection in pregnant women, regardless of trimester. 1, 2

• Azithromycin achieves cure rates of 94-100%, significantly superior to all alternative regimens 1, 3
• This regimen is FDA Pregnancy Category B with extensive clinical experience supporting safety throughout all trimesters, including the first 1, 2
• Single-dose administration ensures excellent compliance compared to multi-day regimens 1
• The American College of Obstetricians and Gynecologists and CDC both recommend azithromycin as the preferred agent 1, 2

Second-Line Alternative: Amoxicillin

If azithromycin is unavailable or not tolerated, amoxicillin 500 mg orally three times daily for 7 days is the preferred alternative. 2, 4

• Amoxicillin causes fewer gastrointestinal side effects than erythromycin-based regimens 2, 5
• Efficacy is comparable to azithromycin in most studies, with cure rates of 95% 2, 5
• This is a safer and better-tolerated option than any erythromycin formulation 5

Lower-Efficacy Alternatives (Use Only When First Two Options Unavailable)

Erythromycin-based regimens have significantly lower efficacy (64-77%) and substantially higher rates of gastrointestinal intolerance: 1, 4

• Erythromycin base 500 mg orally four times daily for 7 days 2, 4
• Erythromycin base 250 mg orally four times daily for 14 days 4
• Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 4
• Erythromycin ethylsuccinate 400 mg orally four times daily for 14 days 4

Absolute Contraindications

Never prescribe these medications during pregnancy: 1, 2, 4

• Doxycycline – teratogenic 1, 2
• Ofloxacin – teratogenic 1, 2
• Levofloxacin – teratogenic 1, 2
• Erythromycin estolate – causes drug-related hepatotoxicity in pregnancy 1, 2, 4
• Clarithromycin – animal teratogen; do not confuse with azithromycin 1, 2

Critical Pitfall to Avoid

Do not confuse azithromycin with clarithromycin. Clarithromycin is teratogenic in animals and must be avoided, while azithromycin is the preferred macrolide for pregnancy. 1, 2

Mandatory Follow-Up Testing

All pregnant women must undergo repeat testing 3 weeks after completing therapy to confirm cure. 1, 2, 4

• This test-of-cure is non-negotiable in pregnancy due to serious maternal and neonatal consequences of persistent infection 1, 4
• Untreated maternal chlamydia leads to perinatal transmission causing neonatal conjunctivitis (5-12 days after birth) and subacute pneumonia (1-3 months of age) 4
• Use nucleic acid amplification testing (NAAT) or culture for the test-of-cure 4

Partner Management (Mandatory)

Sexual partners must be evaluated, tested, and treated if they had sexual contact during the 60 days preceding diagnosis. 1, 2, 4

• Treat the most recent partner even if last contact exceeds 60 days 2
• Patients must abstain from sexual intercourse until both partners complete treatment – meaning 7 days after single-dose azithromycin or after completion of multi-day regimens 2, 4
• Failure to treat partners is the most common cause of apparent treatment failure in pregnant patients 2

Special Populations

• HIV-positive pregnant women receive identical treatment regimens as HIV-negative women 1, 4
• Pregnant women under 25 years of age are at higher risk and should be targeted for screening 1, 4

Neonatal Prophylaxis Note

Standard neonatal ocular prophylaxis with silver nitrate or antibiotic ointments does not prevent chlamydial transmission but should be continued to prevent gonococcal ophthalmia. 4