A 35-year-old woman from Mumbai attends antenatal clinic at 28 weeks gestation. She is asymptomatic but routine serological screening shows RPR 1:64 (positive) and FTA-ABS positive. She has no history of syphilis treatment. Her partner is untested. What is the most appropriate next step in management to prevent congenital syphilis?

Explanation

## Maternal Syphilis & Congenital Prevention **Key Point:** Any pregnant woman with serological evidence of syphilis (regardless of symptoms or stage) must receive penicillin treatment immediately to prevent vertical transmission and congenital syphilis. ### Rationale for Immediate Treatment **High-Yield:** Untreated maternal syphilis has a **50% risk of vertical transmission** and can cause: - Early congenital syphilis (hepatosplenomegaly, rash, jaundice, osteochondritis) - Late congenital syphilis (interstitial keratitis, Hutchinson teeth, saddle nose, saber shins) - Stillbirth or neonatal death **Clinical Pearl:** Penicillin crosses the placenta and is the **only antibiotic proven to prevent congenital syphilis**. Treatment at any gestational age reduces transmission risk; earlier treatment is more effective. ### Treatment Protocol for Pregnant Women | Stage of Syphilis | Recommended Regimen | Rationale | |-------------------|---------------------|----------| | Primary/Secondary/Early latent (<1 yr) | Benzathine PCN G 2.4 MU IM weekly × 3 weeks | Standard first-line; crosses placenta | | Late latent (>1 yr) or tertiary | Benzathine PCN G 2.4 MU IM weekly × 3 weeks | Same as early; tertiary also needs neurosyphilis workup | | Penicillin allergy (non-pregnant) | Doxycycline or azithromycin | **NOT safe in pregnancy** | | Penicillin allergy (pregnant) | Penicillin desensitization, then treatment | Allergy must be overcome; alternatives fail | **Warning:** Azithromycin and doxycycline are **contraindicated in pregnancy** — azithromycin has inadequate placental penetration and doxycycline causes tooth discoloration in the fetus. Penicillin allergy must be managed by desensitization if necessary. ### Why Immediate Treatment Is Non-Negotiable 1. **Gestational age is not a contraindication:** Penicillin is safe at any trimester; benefits far outweigh risks 2. **Partner status is irrelevant to maternal treatment:** The mother is infected and symptomatic (serologically); she must be treated regardless of partner results 3. **Asymptomatic status does not delay treatment:** Serological evidence of syphilis in pregnancy is sufficient indication 4. **Jarisch-Herxheimer reaction is manageable:** Occurs in ~50% of patients; self-limited and not a reason to defer treatment ### Post-Treatment Monitoring - Repeat RPR at delivery to assess treatment response - Neonatal serology and long-bone X-rays at birth - Follow-up RPR in infant at 1, 3, 6, and 12 months