[Analysis on negative conversion of syphilis-specific antibody and related factors in children born to pregnant women with syphilis in China, 2021].

Objective: To understand the negative conversion of syphilis-specific antibody in follow-up in 0-18 months-old children born to pregnant women with syphilis in China in 2021 and analyze the related factors. Methods: The basic information of pregnant women with syphilis and follow-up information of their children in 2021 were extracted from the National Management Information System for the Prevention of mother-to-child transmission of HIV, syphilis and Hepatitis B. The logistic regression model was used to analyze related factors of negative conversion of syphilis-specific antibody. Results: In 2021, a total of 34 201 children was delivered by syphilis-infected pregnant women, and 23 592 (68.98%) children were included in this study. Negative conversion of syphilis-specific antibody occurred in 21 076 (89.34%) children, but not in 2 516 (10.66%) children. Multivariate logistic regression analysis identified several factors associated with a higher probability of the negative conversion of syphilis-specific antibody: prophylactic benzathine penicillin injection at birth (aOR=1.35,95%CI:1.10-1.65), mother's age 26-30 years (aOR=1.22,95%CI:1.01-1.46), 36-40 years (aOR=1.34, 95%CI:1.09-1.64), other ethnic groups (aOR=1.19,95%CI:1.04-1.36), non-syphilis-specific antibody titers less than 1∶8 during pregnancy (aOR=1.56,95%CI:1.37-1.78), penicillin treatment (aOR=1.56,95%CI:1.23-1.98) and standardized treatment (aOR=1.21,95%CI:1.11-1.32). Conclusions: In 2021,the level of syphilitic-specific antibody negative conversion in follow-up in children born to pregnant women with syphilis was high in China. According to the factors associated with syphilis-specific antibody negative conversion, it is necessary to develop the follow-up strategies for the children born to pregnant women.