Maternal and paternal factors associated with congenital syphilis in Shenzhen, China: a prospective cohort study

Maternal and paternal factors create considerable obstacles to the elimination of congenital syphilis (CS). A clear understanding of maternal and paternal factors is important in order to define interventions in every community. This study aimed to investigate the maternal and paternal factors associated with CS. A prospective cohort study was conducted from April 25, 2007 to October 31, 2012 at the Shenzhen Center for Chronic Disease Control and Prevention (SCCDC) in China. We screened 279,334 pregnant women and identified 838 women with syphilis. Finally, a total of 360 women with syphilis were included for analysis. At the end of follow-up, 34 infants [9.4 %, 95 % confidence interval (CI): 6.8–12.9 %] were diagnosed with CS. Following adjustment for confounders, maternal history of syphilis [adjusted risk ratio (aRR) = 0.21], prenatal care (aRR = 0.12), and complete treatment (aRR = 0.22) reduced the risk of infants being infected. Every two-fold increase of titer of non-treponemal antibodies (aRR = 1.88), early stage of syphilis (aRR = 9.59), a shorter length of time between the end of the first treatment to childbirth (aRR = 5.39), and every week of delay in treatment (aRR = 2.25) for maternal syphilis as well as paternal history of cocaine use (aRR = 6.28) and positive (aRR = 3.30) or unknown (aRR = 2.79) status of syphilis increased the risk of infants being infected. CS also increased the risk (aRR = 8.02) of neonatal death. Maternal and paternal factors constituted two separate profiles associated with CS. To become more effective, future strategies for the prevention of CS should be targeted to each profile.