What is the most suitable action for health promotion and illness prevention in a pregnant patient with a history of multiple sexually transmitted diseases (STDs), presenting at the first antenatal visit, to prevent conjunctivitis and blindness in the newborn?

Treatment of Maternal Chlamydia to Prevent Neonatal Conjunctivitis

The most suitable action is B. Azithromycin administration - treating the pregnant mother with azithromycin 1 g orally as a single dose is the most effective strategy for preventing neonatal chlamydial conjunctivitis and blindness. 1

Rationale for Maternal Treatment

Prenatal screening and treatment of pregnant women can prevent chlamydial infection among neonates, making maternal treatment the most effective preventive strategy. 1 This approach addresses the root cause - perinatal transmission occurs when the neonate is exposed to the mother's infected cervix during delivery. 2

Why Maternal Treatment is Superior to Other Options

• Neonatal ocular prophylaxis with silver nitrate solution or antibiotic ointments does NOT prevent perinatal transmission of C. trachomatis from mother to infant, though these agents do prevent gonococcal ophthalmia. 2

• Research confirms that topical prophylaxis has limited efficacy - one study showed chlamydial conjunctivitis rates of 20% with silver nitrate, 14% with erythromycin ointment, and 11% with tetracycline ointment in infants born to infected mothers, with no statistically significant differences. 3

• Treating the mother prevents not only conjunctivitis but also chlamydial pneumonia (which develops in 1-3 months of age) and other neonatal infections of the oropharynx, urogenital tract, and rectum. 2

Recommended Treatment Regimen

Azithromycin 1 g orally as a single dose is the first-line treatment for pregnant women with suspected or confirmed chlamydial infection. 1

Alternative Regimens

• Amoxicillin 500 mg orally three times daily for 7 days 2, 1
• Erythromycin base 500 mg orally four times daily for 7 days 2, 1
• Erythromycin base 250 mg orally four times daily for 14 days 2, 1

Critical Contraindications

• Doxycycline, ofloxacin, levofloxacin, and quinolones are absolutely contraindicated in pregnant women. 1
• Erythromycin estolate is contraindicated during pregnancy due to drug-related hepatotoxicity. 2, 1

Additional Management Considerations

• Test for co-infection with N. gonorrhoeae, as patients infected with gonorrhea are often co-infected with chlamydia. 1

• Repeat testing 3 weeks after completion of therapy is recommended for all pregnant women to ensure therapeutic cure. 1

• Sexual partner(s) must be evaluated and treated to prevent reinfection. 2, 1

Why Other Options Are Inadequate

• Reassurance (Option A) is inappropriate - C. trachomatis is the most frequent identifiable infectious cause of ophthalmia neonatorum and can cause blindness if untreated. 2

• Newborn screening after delivery (Option C) is reactive rather than preventive - by the time conjunctivitis develops (5-12 days after birth), the infant has already been infected and requires treatment with approximately 80% efficacy, potentially requiring a second course. 2

• Referral to infectious disease clinic (Option D) delays definitive treatment - chlamydia treatment in pregnancy is straightforward and should be initiated immediately at the first antenatal visit. 1

Common Pitfalls to Avoid

• Do not rely solely on neonatal ocular prophylaxis - it does not prevent chlamydial transmission. 2

• Do not delay treatment pending specialist referral - this is a primary care intervention with clear guidelines. 1

• Do not forget to screen for other STDs given the patient's history of multiple sexually transmitted diseases. 1