IntroductionOf all syphilis-related pregnancy outcomes, fetal death is certainly the most common one, being directly related to the availability, accessibility and quality of prenatal care. The present study aimed to analyze the underreporting of fetal and infant deaths and other maternal factors associated with congenital syphilis (CS) death.MethodsThis cross-sectional study integrated data of infants that were diagnosed and/or died of CS from the Sistema de Informação de Agravos de Notificação–Sinan (Notifiable Diseases Information System) and the Sistema de Informação de Mortalidade–SIM (Mortality Information System) in Fortaleza, Northeastern Brasil to identify unreported cases of congenital syphilis. We assessed data during the period from 2007 to 2013.ResultsThe underreporting of CS as a cause of fetal or infant death increased from 41 to 415 cases (90.1%) during 2007–2013. Exactly 3,209 cases of CS were identified in Sinan and 6,578 deaths in SIM. After database linkage, we identified 382 cases that were reported in the SIM and SINAN databases consisting of 309 fetal deaths and 73 infant deaths related to CS. From the children notified at Sinan that born alive, 3.0% (78/2,542) died; Out of these, 39 (50.0%) were early and 25 (32.1%) were late neonatal deaths. The proportion of death by CS increased from 0.62 to 5.8 from 2007 to 2013. At logistic regression, the variable that maintained statistical significance with fetal and infant death outcomes was the presence of CS signs and/or symptoms at birth (OR = 3.20; IC 95% 1.54–6.62; p = 0.002).ConclusionsNeonatal and Infant deaths following CS-associated live births are underreported in Northeastern Brazil. Data base linkage identified unreported fetal and neonatal deaths due to CS leading to an increased awareness of fetal/infant mortality due to this infection.