Maternal and congenital syphilis at a national referral center in Peru, 2023–2025

Background Congenital syphilis remains a preventable cause of neonatal morbidity and mortality despite the availability of inexpensive diagnostics and effective treatment. We aimed to evaluate the burden of maternal and congenital syphilis at the Instituto Nacional Materno Perinatal, Peru’s national referral center for maternal and perinatal care. Methods We conducted a cross-sectional study of aggregated, de-identified surveillance data from January 2023 to December 2025. We calculated the prevalence of maternal syphilis and incidence of congenital syphilis, and compared those estimates with World Health Organization (WHO) elimination benchmarks. Results Among 59,598 pregnant people screened, maternal syphilis prevalence ranged between 1.0% and 1.2%. Across 36,094 live births, congenital syphilis incidence ranged between 383 and 526 per 100,000 live births, consistently exceeding the WHO target of 50 per 100,000 live births. Outside facilities identified over half of maternal infections before referral. Reported treatment coverage exceeded 90% among mothers and reached 100% among infants. Conclusions Congenital syphilis incidence consistently exceeded elimination benchmarks despite relatively stable maternal syphilis prevalence, highlighting potential gaps in timely diagnosis and linkage between diagnosis and treatment.