Syphilis is a disease that is found all over the world that causes damaging effects to the fetus through vertical transmission. This study aimed to analyze the processes that trigger the vertical transmission of syphilis through gestational and congenital syphilis notifications. It is a cross-sectional study. The sample totaled 129 notifications of syphilis in pregnant women and 132 notifications of congenital syphilis in the city of Natal, from 2011 to 2015. Data were obtained from the Information System for Disease Notification. The Chi-square, Student's and Fisher's tests were used to verify associations of interest. Diagnosis of maternal syphilis was predominant in the third trimester of pregnancy. Only 1.6% of the pregnant women were registered with an adequate treatment regimen, of these 16.3% had the concomitant treatment with their partners. Of the affected children, 78.8% were registered as asymptomatic. The factors that trigger vertical transmission are related to the late diagnosis of the pregnant woman and sexual partner(s) and the deficiencies in clinical/therapeutic management in relation to the phase of the disease. Strategies of professional training should be adopted to notify and expand the provision of information for epidemiological surveillance, aiming to strengthen care, reduce vertical transmission and enable the continuous analysis of this problem.
Keywords: congenital syphilis; epidemiology; geographic mapping; prenatal care; public health surveillance; vertical transmission of infectious disease.