What is the best course of action for a pregnant woman at 37 weeks gestation with multiple sexually transmitted infections (STIs), including one that can cause conjunctivitis and blindness in the newborn, such as Chlamydia trachomatis?

Treatment of Pregnant Woman at 37 Weeks with Chlamydia Trachomatis

The best course of action is B) give azithromycin 1 g orally as a single dose now to treat the mother, which is the most effective strategy to prevent neonatal conjunctivitis and blindness. 1

Rationale for Maternal Treatment

Treating the mother during pregnancy is the primary prevention strategy for neonatal chlamydial infection. 1, 2 The infection you're concerned about is Chlamydia trachomatis, which causes ophthalmia neonatorum (conjunctivitis developing 5-12 days after birth) and is the most frequent identifiable infectious cause of neonatal conjunctivitis. 3, 4

Why Maternal Treatment is Superior to Other Options:

• Prenatal screening and treatment of pregnant women can prevent chlamydial infection among neonates, making maternal treatment the most effective preventive strategy. 1
• At 37 weeks gestation, you have a critical window to treat the mother before delivery and prevent perinatal transmission during passage through the infected birth canal. 4
• Neonatal ocular prophylaxis with silver nitrate solution or antibiotic ointments does NOT prevent perinatal transmission of C. trachomatis from mother to infant, though it should still be continued for gonococcal ophthalmia prevention. 3, 2

Recommended Treatment Regimen

Azithromycin 1 g orally as a single dose is the first-line treatment for pregnant women with chlamydial infection due to superior efficacy (95% clinical cure rate), excellent compliance with single-dose therapy, and proven safety in pregnancy. 1, 2, 5

Alternative Regimens (if azithromycin is not tolerated):

• Amoxicillin 500 mg orally three times daily for 7 days (92% efficacy, fewer GI side effects than erythromycin). 1, 2, 6
• Erythromycin base 500 mg orally four times daily for 7 days OR 250 mg four times daily for 14 days (64-77% efficacy, more GI side effects). 3, 2

Absolute Contraindications in Pregnancy:

• Doxycycline, ofloxacin, levofloxacin, and all quinolones are absolutely contraindicated. 1, 2
• Erythromycin estolate is contraindicated due to drug-related hepatotoxicity. 3, 1, 2

Why Not the Other Options?

Option A (Refer to Infectious Diseases):

• Unnecessary delay at 37 weeks gestation when delivery is imminent. 1
• Chlamydia treatment in pregnancy is straightforward and within the scope of obstetric practice. 1, 2
• Referral would waste precious time before delivery when the mother could be treated immediately. 1

Option C (Screen Neonate After Birth):

• This is reactive rather than preventive—the neonate would already be exposed during delivery. 4
• While neonatal screening and treatment are important if maternal infection is untreated, prevention through maternal treatment is superior. 1
• If the neonate develops infection, treatment requires erythromycin 50 mg/kg/day divided into four doses for 14 days, which has only 80% efficacy and may require a second course. 3, 4

Essential Follow-Up Management

• Repeat testing 3 weeks after completion of therapy is recommended for all pregnant women to ensure therapeutic cure, given the serious sequelae for both mother and neonate if infection persists. 1, 2
• Sexual partner(s) must be evaluated and treated if they had sexual contact during the 60 days preceding diagnosis to prevent reinfection. 1, 2
• Patients should abstain from sexual intercourse until 7 days after single-dose therapy or until completion of multi-day regimens. 2
• Test for co-infection with N. gonorrhoeae, as patients are often co-infected; if confirmed, add ceftriaxone 250 mg IM as a single dose. 1

Common Pitfalls to Avoid

• Do not delay treatment waiting for culture results—treat presumptively based on clinical suspicion given the multiple STIs and imminent delivery. 1
• Do not rely solely on neonatal prophylaxis—it does not prevent chlamydial transmission. 3, 2
• Do not use doxycycline despite it being standard therapy outside pregnancy—it is teratogenic. 1, 2
• Ensure partner treatment or reinfection rates will be high, negating the benefit of maternal treatment. 1, 2