Seroepidemiological Characteristics and Influencing Factors of Hepatitis B Virus Infection Among Pregnant Women in Nanning City, China (2024–2025): A Cross-Sectional Study

Abstract

Objectives: This cross-sectional study characterized HBV serological profiles and associated factors among pregnant women in Nanning to inform targeted MTCT prevention strategies. Methods: A total of 1935 pregnant women were enrolled via stratified cluster random sampling from October 2024 to May 2025. Five HBV serological markers were quantified by chemiluminescence immunoassay. Multivariable analysis identified factors associated with HBsAg, HBsAb, and HBcAb positivity. HBsAb geometric mean concentration (GMC) and ratio (GMR) were calculated. Results: The overall seropositivity rates (with 95% CI) of HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb were 6.98% (5.92–8.20%), 59.48% (57.28–61.65%), 1.50% (1.05–2.14%), 15.50% (13.96–17.18%), and 33.02% (30.96–35.15%), respectively. HBsAg, HBeAb, and HBcAb positivity increased with age. The HBsAb GMC among uninfected pregnant women was 4.63 mIU/mL (95% CI: 3.72–5.75). Rural pregnant women had lower HBsAb seropositivity than urban counterparts. Unvaccinated women or those with unknown vaccination status showed higher HBsAg, HBeAg, HBeAb, and HBcAb positivity, and lower HBsAb seropositivity, compared with vaccinated women. Advanced age, chronic comorbidities, and HBV exposure were risk factors for HBsAg positivity, whereas HBV vaccination was protective. For HBsAb, higher education and vaccination were protective; advanced age, rural residence, chronic comorbidities, and non-medical occupations were risk factors. For HBcAb, advanced age, chronic comorbidities, and HBV exposure were risk factors, while higher education and vaccination were protective. Conclusions: Pregnant women in Nanning have a high HBV prevalence and insufficient immune protection. Targeted prevention strategies for reproductive-age women are urgently needed to reduce vertical transmission risk.