Abstract
BACKGROUND: Congenital syphilis (CS) in the United States increased 10-fold in the last decade. At a large public hospital in Los Angeles, the numbers of infants born to mothers with untreated syphilis during pregnancy have continued to rise. METHODS: We compiled a retrospective case series from all infant rapid plasma reagin test results from 2022 to 2023 summarizing CS diagnosis and relevant diagnostic criteria. χ2 and Fisher exact tests were used to examine associations between maternal risk factors and CS diagnosis. RESULTS: Maternal syphilis complicated 97 of 2367 live births (4.1%) at our institution. Approximately 36% (n = 35) of infants born to mothers with a history of syphilis (n = 94) were born to a mother with inadequately treated syphilis or concern for reinfection. Infants with exposure to maternal syphilis were mostly asymptomatic at birth but had a high frequency of abnormalities in laboratory and radiographic evaluation. Compared with infants with less likely or unlikely CS, mothers of infants with highly probable or possible CS were more likely to have methamphetamine use during pregnancy (41% vs. 69%, P = 0.02), cocaine use during pregnancy (2% vs. 14%, P = 0.03), opiate use during pregnancy (7% vs. 37%, P = <0.001), and no prenatal care (7% vs. 40%, P ≤ 0.001). CONCLUSIONS: This case series identified maternal substance use and no prenatal care as risk factors for highly probable or possible CS, underscoring the vulnerability of this population and informing future work in prevention of this disease.