Preconception syphilis seroprevalence and association with duration of marriage and age among married individuals in Guangdong Province, China: A population-based cross-sectional study

Abstract

Background Duration of marriage (DoM) and age are important characteristics of married individuals, who are the critical population for eliminating mother-to-child transmission (MTCT) of syphilis. A deep understanding of the preconception syphilis seroprevalence (PSS) and its distribution among this population may be able to help to eliminate MTCT. However, few population-based epidemiological studies have been focused on this group, and the association of DoM and age with PSS remains unclear. Methodology/Principal findings This study used data from 4,826,214 married individuals aged 21–49 years who participated in the National Free Preconception Health Examination Project in Guangdong Province, China, between 2014 and 2019. Syphilis was screened using the rapid plasma reagin (RPR) test. The seroprevalence time series, seroprevalence map, and hot spot analysis (HSA) were employed to visualize the spatiotemporal distribution. The restricted cubic spline (RCS) based on multivariate logistic regression was used to model the association of DoM and age with PSS. The interactions on the additive scale of DoM and age were also assessed. The PSS was 266.61 per 100,000 persons (95% CI: 262.03–271.24) and the burden was higher in economically underdeveloped area within the province. A strong J-shaped non-linearity association was observed between age and PSS. Specifically, the risk of seropositivity was relatively flat until 27 years of age among men and increased rapidly afterwards, with an adjusted odds ratio (aOR) of 1.13 (95% CI: 1.12–1.13) per unit. Among women, the risk of seropositivity was relatively flat until 25 years of age and increased rapidly afterwards with an aOR of 1.08 (95% CI: 1.08–1.09) per unit. DoM was negatively associated with PSS among married individuals. Moreover, the combined effects of age and DoM appeared to be synergistic. Conclusions/Significance Our findings suggest that attention should be paid to preventing syphilis in underdeveloped areas and that syphilis screening in newly married individuals who are in their late 20s or older should be recommended. Additionally, early syphilis prevention strategies should be implemented among young people as early as possible.

Factors associated with adverse pregnancy outcomes of maternal syphilis in Henan, China, 2016–2022

“…Overall, 57.98% of the 7030 pregnant women included in this study were reproductive active period (25-35 years). The majority of the pregnant women included has education levels of junior high school or below, and their occupations were mainly farmers, which was consistent with the characteristic distribution of the syphilis population in China [18,19]. It…”

“…Overall, 57.98% of the 7030 pregnant women included in this study were reproductive active period (25–35 years). The majority of the pregnant women included has education levels of junior high school or below, and their occupations were mainly farmers, which was consistent with the characteristic distribution of the syphilis population in China [18, 19]. It was suggested that health education on syphilis prevention and control should focus on women in the reproductive active period and women of childbearing age in rural areas.…”

Preconception Blood Pressure and Adverse Pregnancy Outcomes: A Population-Based Cohort Study

“…The detailed design, organization, and quality control have been published previously. 29,30 Briefly, there are 3 main phases in which detailed information was collected: preconception health examinations, early pregnancy follow-up, and…”

“…In the multivariable model, we additionally adjusted for maternal higher education (defined as senior high school, college, or higher; yes/no), preconception body mass index (BMI, continuous), diabetes (yes/no), preconception thyrotropin levels (continuous), ethnic origin (Han/others), household registration (rural/ urban), economic pressure (yes/no), smoking during pregnancy (yes/no), drinking during pregnancy (yes/no), passive smoking during pregnancy (yes/no), first gestation (yes/no), history of APOs (yes/no), and location (Pearl River Delta, East wing, West wing, or mountainous area). 30 The adjusted absolute risk differences (measured in percentage points) were calculated by marginal structural binomial regression models. 25 Inverse probability weights were computed using logistic models with the same covariates as the multivariable model predicting aRRs.…”

“…In the post hoc analysis, we applied piecewise regression models to calculate the aRR per SD increase in SBP and DBP. 30 The covariates in the piecewise and spline models were the same as those in the multivariable model; moreover, SBP and DBP were mutually adjusted as continuous variables.…”