(435) Characterizing Congenital Syphilis in California Between 2008-2019

We performed a retrospective cohort study among singleton, non-anomalous births delivered between 23 and 42 weeks in California between 2008 and 2019. Overall rates of maternal and congenital syphilis per 100,000 births were plotted across birth years of 2008-2019. Maternal demographic factors of interest included race/ethnicity, age, pre-pregnancy body mass index (BMI), parity, insurance type, and education level.

Results: The rate of congenital syphilis in California between 2008-2019 mirrored the steep rise in the rate of maternal syphilis, but did not see as dramatic of an increase as the maternal syphilis rate between 2016-2019 (Figure 1). Relative to those unaffected by congenital syphilis, infants with congenital syphilis were more likely to have mothers who were non-Hispanic Black (11.4% vs. 4.9%) or Hispanic (61.2% vs. 50.9%); under 20 (7.4% vs. 6.6%) or between 20-34 years old (78.5% vs 73.7%); overweight (30.2% vs. 26.3%) or obese (26.1% vs. 22.5%); multiparous (72.3% vs. 60.8%); had public insurance (90.9% vs. 52.2%); and had completed high school education or less. (72.9% vs. 44.0%).

Conclusion: Congenital syphilis rates have increased alongside maternal syphilis rates in California between 2008-2019. Mothers of infants with congenital syphilis differ from the mothers of those who do not have congenital syphilis by numerous demographic factors, emphasizing the need to investigate the underlying structural factors leading to disparities in congenital syphilis rates.