Congenital syphilis is a vertical infection of high public health relevance, associated with adverse perinatal outcomes including miscarriage, stillbirth, and irreversible neurosensory sequelae. It is a preventable condition through early diagnosis and appropriate treatment of the pregnant woman and her partner(s). This study aims to describe the evolution of confirmed congenital syphilis cases in children under one year old in the municipality of Santa Maria – RS, between 2020 and 2023, highlighting the epidemiological relevance of the data to support surveillance strategies and improve prenatal care.

Descriptive, retrospective study based on records from the Notifiable Diseases Information System (SINAN), accessed via TabNet/DATASUS. Confirmed cases of congenital syphilis in residents of Santa Maria – RS, notified between 2020 and 2023, were included. The variables analyzed were the annual absolute totals of cases in children under one year old, categorized by notification year.

Between 2020 and 2023, 64, 88, 77, and 124 cases of congenital syphilis were reported in Santa Maria – RS, respectively. There was a 37.5% increase between 2020 and 2021, followed by a slight reduction in 2022 (-12.5%) and a significant increase of 61% in 2023, reaching the highest value of the series. This fluctuating trend indicates persistent failures in preventing vertical transmission, possibly related to late testing, ineffective treatment of gestational syphilis, loss to follow-up, or inadequate partner management. The data reinforce the need to assess the coverage and effectiveness of sexual and reproductive health interventions in the municipality.

The fluctuation and resurgence of congenital syphilis cases in Santa Maria reveal gaps in epidemiological surveillance and prenatal care. Continuous analysis of indicators, together with team training, expanded testing in the first and third trimesters, active partner tracing, and guaranteed treatment supplies, constitute essential strategies to interrupt the transmission chain and achieve the elimination goals proposed by the Ministry of Health.