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CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
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Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 1

Category: Infectious Diseases

Poster Session 1

(266) Possible syphilis in pregnancy after prior treatment: low neonatal morbidity but a clinical conundrum

Wednesday, February 11, 2026
10:30 AM - 12:00 PM  
Objective:
Examine syphilis management and neonatal outcomes in pregnant patients with prior syphilis treatment and possible infection, versus clinically active infection

Study Design:
This is a retrospective cohort study of pregnant individuals with reactive syphilis serologies at a large public hospital. Treatment history, if available, was confirmed with local public health officials. We excluded individuals considered serofast (serologic response, adequate prior treatment, and no concern for reinfection) and those with documented reinfection (new symptoms, fourfold titer increase or newly reactive RPR).  We compared demographics, comorbidities, syphilis characteristics and neonatal outcomes in the remainder considered to have possible infection (+/- serologic response, uncertain adequacy of treatment, or persistent positive titers) vs no reported treatment (active syphilis) prior to the current pregnancy.

Results:
From January 1, 2010, through June 30, 2025, 898 patients delivered with reactive serologies, including 576(64.1%) reporting no prior treatment (active syphilis) and 322(35.9%) reporting prior treatment. Of the latter, excluded were 149(16 .6%) serofast and 50(5.6%) with documented reinfection. The 123(13.7%) with prior treatment (possible syphilis) had lower RPR titers and were more likely staged as latent, late or unknown duration stage than those with active syphilis. Of these with possible infection, 109 (89%) were given at least 2.4M units IM BPG despite 52(42%) having confirmed previous adequate treatment. Stillbirths from congenital syphilis occurred in 0 previously treated and 8(1%) with active syphilis. Congenital syphilis was less frequent among previously treated (4[3%] vs 86[15%], p< 0.001). Nonetheless, 30% of neonates in both groups were treated for possible congenital syphilis with 10 days of IV penicillin (p=0.99). 

Conclusion:
Distinguishing active syphilis infection in seroreactive, previously treated individuals remains a challenge, although neonatal morbidity is low. Improved diagnostics would impact both maternal and neonatal management in this population.