Incidence and Characteristics of Infants with Congenital Syphilis in U.S. NICUs from 2011 to 2020

Congenital syphilis presents a significant public health problem. Since 2012, there has been a dramatic increase in reported cases of congenital syphilis. However, characteristics of these cases have not been well detailed. This study sought to describe recent trends in the incidence of congenital syphilis, demographic characteristics, hospital treatment, and outcomes of these infants.A retrospective cohort study of all infants in the Pediatrix Clinical Data Warehouse (CDW; a large multicenter de-identified dataset) from 2011 to 2020 was performed. We identified infants with a diagnosis of congenital syphilis and evaluated trends in overall prevalence, as well as changes in maternal and infant characteristics over time.Of 842,928 infants discharged over the study period, we identified 1,625 infants with congenital syphilis. Between 2011 and 2020, the prevalence of congenital syphilis increased from 0.8 to 4.6 per 1,000 neonatal intensive care unit (NICU) admissions (p < 0.05). Most infants were treated with penicillin for 10 days, and the median length of stay was 10 days. Mortality was 0.9% in this cohort. Maternal coinfection with Hepatitis C was unchanged but remained significantly above national rates of Hepatitis C infection in pregnant women. Maternal drug use in infants born with congenital syphilis increased from 6.1 to 24.6% over the decade of the study. The distribution of maternal race changed over the decade, with significantly more mothers identified as White or Other in 2019 to 2020 as compared to the earlier cohorts. There was a concurrent decrease in mothers who identified as Hispanic or African American.From 2011 to 2020, the prevalence of congenital syphilis in the Pediatrix CDW increased by 475%. Although infant characteristics remained similar over time, there was a notable increase in maternal drug use and a persistently elevated risk of other sexually transmitted diseases. Further research examining the association between maternal comorbidities and congenital syphilis is necessary. · Between 2011 and 2020, the prevalence of congenital syphilis increased by 475%.. · Mortality of congenital syphilis in live-borns stayed steady at 0.9%.. · Maternal coinfection with other sexually transmitted diseases remained high over the decade.. · Maternal drug use in infants with congenital syphilis increased significantly over the decade..