Congenital syphilis as a failure of the maternal–fetal prevention cascade: Clinical implications for pregnant migrant and structurally vulnerable women in high-income settings — an ESCMID study group for infections in Travellers and migrants (ESGITM) perspective

Background: Congenital syphilis remains a preventable but persistent cause of fetal loss, neonatal morbidity, and early-life complications. In high-income settings, its occurrence rarely reflects the absence of diagnostic tools or effective therapy; but more often exposes missed opportunities across antenatal care, sexually transmitted infection prevention, maternal treatment, partner management, and neonatal follow-up. This review investigates congenital syphilis from the viewpoint of the possible failures of the maternal–fetal prevention pathway, with a specific focus on pregnant migrant and structurally vulnerable women. Methods: This narrative clinical review synthesizes epidemiological data, international guidelines, surveillance reports, and selects peer-reviewed literature on maternal and congenital syphilis, antenatal screening, vertical transmission, penicillin treatment, neonatal assessment, migrant health, and structural barriers to care. Relevant sources available up to june 2026 have been identified through targeted searches of PubMed/MEDLINE, institutional websites, and guideline repositories, including those of WHO, CDC, ECDC, USPSTF, and BASHH. Results: Congenital syphilis may result from inadequacies at multiple points: delayed antenatal access, missed or late screening, incomplete or non-stage-appropriate treatment, untreated partners, reinfection, poor documentation, and inadequate neonatal follow-up. Pregnant migrant women and structurally vulnerable women may face additional barriers, including language difficulties, administrative insecurity, unstable housing, stigma, unsafe partner disclosure, mobility, and fragmented care across the various emergency centres, sexual health, obstetric, and neonatal services. Prevention should therefore prioritize reducing missed opportunities through early and repeated screening when indicated, same-visit testing when follow-up is uncertain, rapid linkage between antenatal and STI services, quantitative non-treponemal testing, penicillin-based stage-appropriate treatment, safe partner management, and clear maternal–neonatal documentation. Conclusions: Congenital syphilis should be considered a sentinel event revealing failings in antenatal care, STI prevention, migrant health access, and continuity of care. For pregnant migrant and structurally vulnerable women, prevention requires integrated, accessible, and safely coordinated maternal–neonatal pathways.