Azithromycin Administration to the Mother Now
The most suitable approach is azithromycin 1 g orally as a single dose administered to the mother immediately (Option B), as this is the CDC-recommended first-line treatment for chlamydial infection in pregnancy and represents the most effective strategy to prevent neonatal conjunctivitis and pneumonia. 1
Why Maternal Treatment is Essential
The clinical scenario describes a pregnant woman at 37 weeks with multiple STD history, and the concern about conjunctivitis and blindness in the newborn points directly to Chlamydia trachomatis infection. Here's the algorithmic approach:
Primary Prevention Through Maternal Treatment
Prenatal screening and treatment of pregnant women is the most effective way to prevent chlamydial infection in neonates, as neonatal infection results from perinatal exposure to the mother's infected cervix during delivery. 2, 1
Azithromycin 1 g orally as a single dose is the CDC-recommended first-line treatment for pregnant women with suspected or confirmed chlamydial infection. 1
The prevalence of C. trachomatis among pregnant women exceeds 5% regardless of race/ethnicity or socioeconomic status, and this patient's history of multiple STDs places her at particularly high risk. 2
Why Other Options Are Inadequate
Reassurance (Option A) is inappropriate because untreated maternal chlamydial infection has an 18-50% transmission rate to neonates, causing conjunctivitis in 5-12 days after birth and potentially pneumonia at 1-3 months. 2
Newborn screening after delivery (Option C) is reactive rather than preventive and misses the opportunity to prevent transmission entirely through maternal treatment. 1
Neonatal ocular prophylaxis with erythromycin ointment does NOT prevent perinatal transmission of chlamydia from mother to infant, though it does prevent gonococcal ophthalmia and should still be administered. 2, 3
Referral to infectious disease clinic (Option D) causes unnecessary delay when immediate treatment with azithromycin is indicated and can be administered by the obstetrician. 1
Critical Clinical Considerations
Timing is Crucial
At 37 weeks gestation, delivery is imminent, making immediate maternal treatment essential to reduce bacterial load before the infant passes through the birth canal. 1
Treatment should be initiated at this first antenatal visit without waiting for confirmatory testing, given the high-risk history. 1
Alternative Regimens if Azithromycin Unavailable
Amoxicillin 500 mg orally three times daily for 7 days is an acceptable alternative. 1
Erythromycin base 500 mg orally four times daily for 7 days or 250 mg four times daily for 14 days can be used, though gastrointestinal side effects may reduce compliance. 2, 1
Never use doxycycline, ofloxacin, levofloxacin, or erythromycin estolate in pregnancy - these are absolutely contraindicated. 1
Additional Management Steps
Test for co-infection with N. gonorrhoeae, as patients with gonorrhea are often co-infected with chlamydia; if positive, add ceftriaxone 250 mg IM as a single dose. 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 of the mother and subsequent transmission to the infant. 2, 1
Common Pitfalls to Avoid
Do not rely solely on neonatal prophylaxis: Topical erythromycin ointment given to newborns prevents gonococcal but not chlamydial ophthalmia, and systemic treatment of infected infants is only 80% effective, often requiring a second course. 2, 3
Do not delay treatment for culture confirmation: Given the high-risk history and imminent delivery, empiric treatment is appropriate. 1
Do not forget that chlamydial conjunctivitis is just one manifestation: Untreated neonatal infection can also cause pneumonia at 1-3 months of age and asymptomatic infections of the oropharynx, genital tract, and rectum. 2