Comparison of the Epidemiological Profile of Gestational and Congenital Syphilis in Southern Brazil (2014–2024)

Syphilis is a sexually transmitted infection (STI) caused by Treponema pallidum , with vertical transmission potential leading to severe outcomes such as blindness, deafness, and malformations. Despite public health guidelines for diagnosis and treatment, Southern Brazil maintains high incidence rates. This study aimed to compare the profiles of gestational and congenital syphilis cases between 2014 and 2024. Descriptive study using data from the National Notifiable Diseases Information System (SINAN) for Rio Grande do Sul (RS), Santa Catarina (SC), and Paraná (PR) from January 2014 to December 2024. Sociodemographic and clinical variables were analyzed. As the study used anonymous public data, ethics approval was waived under Resolution No. 510/2016. There were 93,516 cases of gestational syphilis and 33,261 of congenital syphilis. Congenital syphilis peaked in 2017 (3,597 cases) and reached its lowest in 2024 (1,493). Gestational syphilis peaked in 2022 in RS (5,269) and SC (3,045), and in 2023 in PR (4,261). Congenital cases peaked in 2018 (SC), 2021 (RS), and 2023 (PR). The predominant maternal age was 20–39 years; for congenital cases, mothers aged 20–24 years (34.7%). Education levels were mostly high school complete (21.4%) and incomplete elementary school (17.3%). White race/color was the most prevalent in both conditions, which is related to the demographic composition of the Southern region, where this population is the majority.The latent form predominated in pregnancy (32,268 cases), while recent clinical form predominated in congenital cases (30,377). There were 1,910 reports of miscarriage/stillbirth and 651 deaths among 30,420 outcomes. Among congenital cases, 84.4% of mothers received prenatal care, though often late or inadequately managed. Only 22.3% of partners were treated, hindering transmission interruption. The persistence of vertical syphilis transmission in Southern Brazil reveals weaknesses in early screening, prenatal adherence, timely treatment, and partner involvement. Strengthening primary care and improving quality of gestational care are essential strategies for syphilis control.