Background: With the coronavirus disease 19 (COVID-19) pandemic, providers and patients limited health care visits, fearing that they would increase a patient's risk of exposure to the virus. Experts have recommended that prenatal care include telehealth, and that ultrasound and blood draws be combined during in-person visits. Our objective was to compare incidence and factors associated with congenital syphilis (CS) cases in Chicago, Illinois before and after the COVID-19 pandemic. Methods: CS surveillance data reported to the Chicago Department of Public Health (CDPH) between January 1, 2015, and December 31, 2021 were reviewed using CS Case Investigation reports, field notes, patient interviews, and medical record abstraction when available. Missed opportunities were classified according to CDC categories. Chi square test was used with significance set as p< .05. Results: Between 2015 and 2019, the number of reported CS cases in Chicago decreased from 24 to 9 (Table 1). This trend abruptly shifted in 2020, with 19 CS cases reported, and 25 were reported in 2021. In 2020, the proportion (52.6%) of CS cases associated with late identification of seroconversion during pregnancy was higher than in all previous years (17.4%, p< .001). In 2021, the highest proportion, 48% (12/25), of CS cases were among females who did not receive prenatal care. Conclusion: Dramatic increases in the number of reported CS cases during the pandemic associated with the identification of seroconversion during pregnancy might be associated with non-adherence to prenatal visits secondary to fear of Covid. Telehealth prenatal visits may have resulted in limited opportunity for syphilis screening during the pregnancy. Avoidance of STI clinics or decreased access because of pandemic-associated closures may have resulted in fewer partners getting treatment for infections. Pregnant people remain at high risk of Covid infection, especially because of vaccine hesitancy. Prenatal care providers must create new practice models that promote engagement in care, and screening for syphilis must continue according to state-specific recommendations. [ABSTRACT FROM AUTHOR]