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

1. Introduction

Hepatitis B virus-related viral hepatitis continues to pose a severe global public health threat, exhibiting endemic prevalence in high-risk regions across Asia and Africa. Epidemiological disparities in HBV endemicity are evident worldwide: the carrier rate remains low at 0.1%–2.0% in the United States and Western Europe, whereas most countries in Africa and Asia sustain a substantially higher prevalence of 8%–20% [1]. According to the World Health Organization (WHO), a total of 254 million individuals globally were living with chronic HBV infection in 2022, with 1.2 million new infections documented annually. HBV-induced end-stage liver diseases, including liver cirrhosis and primary hepatocellular carcinoma (HCC), cause approximately 1.1 million deaths each year, over 85% of which occur in low- and middle-income countries, highlighting the disproportionate global disease burden in resource-limited settings [2,3].

China bears the highest HBV-related disease burden worldwide and is classified as a country with moderate-to-high HBV endemicity. Currently, more than 90 million people in China live with chronic HBV infection, and over 300,000 HBV-attributable deaths occur annually, accounting for nearly half of the global mortality from HBV-related diseases [4,5]. Notably, HBV prevalence varies substantially across geographical regions and population subgroups in China, making the country a critical battleground for achieving the WHO global goal of eliminating hepatitis B by 2030 [6].

Mother-to-child transmission (MTCT) is the dominant route of HBV transmission, responsible for approximately 90% of all primary HBV infections. Both perinatal and non-perinatal MTCT facilitate sustained viral circulation in communities, leading to long-term endemicity. Neonates infected with HBV during delivery have a 95% probability of progressing to chronic infection, and 15%–40% of these chronically infected children will develop irreversible liver lesions, including cirrhosis and HCC, in adulthood [7,8,9]. Given the critical role of MTCT in the persistence of the HBV epidemic, the WHO has ranked MTCT prevention as one of the five core strategies for global hepatitis B elimination by 2030 [6].

Mother-to-child transmission (MTCT) is the dominant route of HBV transmission, responsible for approximately 90% of all primary HBV infections. Both perinatal and non-perinatal MTCT facilitate sustained viral circulation in communities, leading to long-term endemicity. Neonates infected with HBV during delivery have a 95% probability of progressing to chronic infection, and 15%–40% of these chronically infected children will develop irreversible liver lesions, including cirrhosis and HCC, in adulthood [7,8,9]. Given the critical role of MTCT in HBV epidemic persistence, the WHO has ranked MTCT prevention as one of the five core strategies for global hepatitis B elimination by 2030 [6].

Over the past three decades, China has steadily established and optimized a comprehensive intervention system to block HBV MTCT. In 1992, neonatal hepatitis B vaccination was incorporated into the national routine immunization program. In 2002, childhood hepatitis B vaccination was integrated into the national Expanded Programme on Immunization (EPI) with full government funding, which dramatically improved national vaccination coverage [10]. In 2015, the integrated prevention of mother-to-child transmission (iPMTCT) program targeting HIV, syphilis, and hepatitis B achieved full nationwide coverage, elevating the HBV screening rate among pregnant women to over 99% [11]. Benefiting from continuous policy optimization and standardized pediatric immunization management, China’s overall HBV prevalence declined markedly from 9.72% in 1992 to 5.86% in 2020. In particular, the hepatitis B surface antigen (HBsAg) positive rate among individuals aged 0–29 years has dropped to 0.3% [10,12,13]. These remarkable achievements have transformed China from a high-endemic to a moderate-endemic region, with the most prominent prevention effects observed in pediatric populations [6].

Currently, the combined immunoprophylaxis regimen of the hepatitis B vaccine and hepatitis B immunoglobulin (HBIG) administered within 12 hours of birth has been universally adopted for HBV MTCT blocking in China. However, high maternal HBV viral load is well recognized as the leading independent risk factor for immunoprophylaxis failure and residual vertical transmission [14,15,16]. Despite remarkable progress in pediatric prevention, the HBV prevalence among pregnant women in China has not declined significantly. In 2020, the national HBV prevalence among pregnant women reached 6.64%, which was higher than that of the general population. Moreover, HBV infection among pregnant women presents obvious geographical clustering, predominantly concentrated in southern China, with provincial prevalence rates ranging from 1.53% to 11.9%. These findings indicate that pregnant women remain a key high-risk population for HBV prevention, with persistent and heavy disease burdens [17,18,19,20,21]. To address this challenge, China issued the Action Plan for Eliminating Mother-to-Child Transmission of HIV, Syphilis and Hepatitis B (2022–2025) in 2022, which prioritizes HBV infection prevention among women of childbearing age to fundamentally reduce the risk of vertical transmission.

Guangxi Zhuang Autonomous Region, located in southwestern China, is a high-endemic area for maternal HBV infection. Although the regional HBV prevalence among reproductive women has shown a mild downward trend in recent years, it remains as high as 9.84%, posing enormous challenges to local HBV prevention and control [21,22]. Supported by the national EPI policy, the timely neonatal hepatitis B vaccination rate within 24 hours after birth and the catch-up vaccination rate among children under 15 years old in Guangxi have both exceeded 90%. Since 2015, the HBIG injection coverage of infants born to HBsAg-positive mothers has remained above 99%, and the regional HBV MTCT rate was controlled below 0.36% in 2024, demonstrating substantial progress in MTCT intervention [23,24].

As the capital city of Guangxi, Nanning has long suffered from a high hepatitis B incidence. The reported incidence fluctuated between 71.84/100,000 and 126.53/100,000 from 2015 to 2022, with an overall rising trend [25]. Adult populations constitute the majority of HBV cases in this region, and persistent HBV prevalence among pregnant women continues to hinder local MTCT elimination efforts. Therefore, this cross-sectional study aimed to investigate the seroepidemiological characteristics and influencing factors of HBV infection among pregnant women in Nanning City, so as to provide evidence-based support for the formulation of targeted and localized HBV prevention and control strategies.

2. Materials and Methods

2.1. Setting and Participants

This study adopted a stratified cluster random sampling design to recruit pregnant women receiving prenatal care from October 2024 to May 2025 in Nanning, China. Five representative medical institutions covering urban, suburban, and rural areas were selected as survey sites, including the First People’s Hospital of Nanning in Qingxiu District, the Second People’s Hospital of Nanning in Jiangnan District, Binyang Maternal and Child Health Hospital, Longan County People’s Hospital, and Yongning District People’s Hospital. Inclusion criteria were: (1) having undergone prenatal examinations at these institutions from October 2024 to May 2025; (2) maintaining a maternal health management record; (3) current residence in Nanning; (4) providing informed consent and cooperating with the survey. Exclusion criteria were: (1) the presence of severe underlying conditions such as significant hepatic or renal dysfunction or malignant tumors; (2) cognitive impairment preventing questionnaire completion; (3) refusal of blood sample collection. The required sample size was calculated based on the formula n = Z²P(1−P)/d² , with α = 0.05, Z = 1.96, expected HBV prevalence P = 7.18%, and permissible error d = 0.015. This study was approved by the Ethics Review Committee of the Nanning Center for Disease Control and Prevention (Approval No. 2024024, date 2024-10-17), and all participants provided written informed consent prior to enrollment.

2.2. Survey Content and Field Investigation

A self-designed structured questionnaire was used to collect participant information through face-to-face interviews conducted by uniformly trained investigators. The questionnaire covered three main dimensions: sociodemographic characteristics (age, residential location, ethnicity, occupation, educational level, and monthly household per capita income); health-related behavioral and historical factors (chronic comorbidities, surgical history, blood transfusion history, acupuncture exposure, syringe sharing, and shared daily necessities); and HBV-related characteristics (hepatitis B vaccination history, vaccination interval, and daily exposure to HBV patients or carriers). All questionnaires were checked immediately after completion to supplement missing information and correct logical errors, ensuring high data quality.

2.3. Specimen Collection and Laboratory Detection

Venous blood samples of 3–4 mL were collected from each participant and placed in non-anticoagulant tubes. After standing at room temperature for 30 minutes, the blood samples were centrifuged at 3000 rpm for 10 minutes to separate the serum. The isolated serum specimens were stored at -80 ℃ until detection. All samples were transported to the clinical laboratory of the Second People’s Hospital of Nanning via professional cold-chain vehicles for unified testing. Serum levels of five HBV serological markers, including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb, were quantitatively measured using a chemiluminescence immunoassay. Detection reagents were purchased from Zhengzhou Autobio Diagnostics Co., Ltd., and all experimental operations were strictly performed in accordance with official reagent instructions and standard laboratory operating procedures. The positive cutoff values were defined as follows: HBsAg > 0.05 IU/mL, HBsAb > 10 mIU/mL, HBeAg > 0.1 IU/mL, HBeAb > 0.15 PEIU/mL, and HBcAb > 0.7 PEIU/mL.

2.4. Definition of HBV Infection Status

According to the serological profiles of the five HBV markers, participants were classified into the uninfected and infected groups. Uninfected individuals included susceptible subjects (all five markers negative) and immune subjects (isolated HBsAb positivity). Infected cases were further subdivided into four categories: previous or occult HBV infection (HBsAg-negative with positive core or e-antibodies), isolated HBsAg carriage (only HBsAg positive), inactive HBV infection (HBsAg-positive, HBeAb-positive, and HBcAb-positive, i.e., “small triple positive”), and active HBV infection (HBsAg-positive, HBeAg-positive, and HBcAb-positive, i.e., “large triple positive”). The detailed classification criteria based on HBV serological markers are shown in Table 1.

2.5. Statistical Analyses

Questionnaire data were entered and organized using WPS 2019 software version, with a database established and double-entry verification performed by two individuals. Statistical analysis was conducted using R 4.5.1 software; the geometric mean concentration (GMC) of antibodies was analyzed using the Kruskal-Wallis test, while categorical data were analyzed using the chisquare test. Variables with P < 0.05 in univariate analysis were included in a multivariate unconditional logistic regression model to investigate the influencing factors of HBsAg, HBsAb, and HBcAb positivity rates, with odds ratios (OR) and 95% confidence intervals (95% CI) calculated. The significance level was set at α = 0.05, with P < 0.05 indicating statistical significance.

3. Results

3.1. Characteristics of Subjects

A total of 1935 valid questionnaires were collected in this study, yielding an effective response rate of 96.75%. The age of enrolled pregnant women ranged from 14 to 47 years, with a mean age of 31.15 ± 5.45 years. All participants were stratified into five age groups: 14– years (12.71%), 25– years (30.13%), 30– years (31.78%), 35– years (19.90%), and 40– years (5.48%). In terms of residential distribution, 44.13% of participants lived in urban areas, 40.10% in county and township areas, and 15.76% in rural areas. Ethnically, the cohort consisted of 51.78% Han population, 45.06% Zhuang population, and 3.15% other ethnic groups. For occupational distribution, self-employed individuals accounted for the largest proportion (41.81%), while all other occupational categories individually accounted for less than 11% of participants. Regarding educational level, 27.65% of participants had junior high school education or below, 20.31% had senior high or technical secondary school education, 23.41% held college diploma degrees, 26.93% had bachelor’s degrees, and only 1.71% had postgraduate education or above. Household per capita monthly income was categorized as follows: 20.67% below 2000 CNY, 56.49% between 2000 and 4999 CNY, 18.14% between 5000 and 9999 CNY, and 4.70% no less than 10000 CNY. In terms of health status, only 2.43% of participants reported chronic comorbidities, whereas 97.57% had no underlying diseases. Regarding HBV vaccination history, 12.25% had no vaccination experience, 5.48% had a vaccination interval of less than five years, 60.16% had a vaccination interval of five years or longer, and 22.12% had unclear vaccination records. In terms of parity, 43.05% of participants had one child, 33.44% had two children, and 23.51% had three or more children.

3.2. Distribution of HBV Serological Marker Patterns

According to the comprehensive serological profiles of the five HBV markers, 66.93% of participants were classified as uninfected, and 33.07% as HBV-infected. Among uninfected individuals, 30.70% (594/1935) were susceptible with all serological markers negative, and 36.23% (701/1935) achieved an effective immune status with isolated HBsAb positivity. Among infected participants, 26.10% (505/1935) presented previous or occult HBV infection, 1.40% (27/1935) had active HBV infection (large triple positive), and 5.58% (108/1935) had inactive HBV infection (small triple positive). Age-stratified analysis revealed a distinct trend in HBV infection status. The proportion of uninfected individuals gradually decreased with advancing age, while the proportion of HBV-infected individuals increased progressively with age, and this trend difference was statistically significant (P < 0.001) (Table 2).

3.3. Seroprevalence of Five HBV Serological Markers

3.3.1. Overall Positive Rates

The overall seropositive rates of the five HBV markers among 1935 pregnant women were calculated. The positive rates of HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb were 6.98% (135/1935), 59.48% (1151/1935), 1.50% (29/1935), 15.50% (300/1935), and 33.02% (639/1935), respectively.

3.3.2. Serological Profiles Stratified by Age, Residence, Occupation, Ethnicity, Education and Household Income

Age-stratified analysis revealed distinct variations in HBV serological patterns across age subgroups. The positive rates of HBsAg in the 14-, 25-, 30-, 35-, and 40-year age groups were 2.45%, 3.94%, 8.14%, 10.36%, and 15.09%, respectively; the corresponding HBsAb positive rates were 43.27%, 62.16%, 59.93%, 63.47%, and 65.09%; HBeAg positive rates were 1.63%, 1.03%, 1.79%, 1.55%, and 1.89%; HBeAb positive rates were 3.67%, 9.25%, 17.26%, 23.32%, and 38.68%; and HBcAb positive rates were 12.65%, 22.60%, 36.97%, 46.89%, and 64.15%. The 14-year group had the lowest positive rates of HBsAg, HBsAb, HBeAb, and HBcAb, while the 40-year group had the highest rates. The positive rates of HBsAg, HBeAb, and HBcAb increased significantly with age (all P < 0.001). No significant age-related difference was observed in HBeAg positivity (P > 0.05) (Table 3).

Significant urban–rural disparities were observed in HBV serological status. The HBsAg positive rates in urban, county and township, and rural areas were 5.74%, 6.70%, and 11.15%, respectively, while HBsAb positive rates were 66.39%, 56.57%, and 47.54%; HBeAg positive rates were 1.64%, 1.29%, and 1.64%; HBeAb positive rates were 13.58%, 15.21%, and 21.64%; and HBcAb positive rates were 32.08%, 32.47%, and 37.05%. Significant regional differences were found in the positive rates of HBsAg (P = 0.006), HBsAb (P < 0.001), and HBeAb (P = 0.004), while HBeAg and HBcAb positivity showed no significant difference across regions (P > 0.05). Rural pregnant women had higher positive rates of HBsAg and HBeAb but a lower HBsAb positive rate compared with those in urban and county-township areas (Table 3).

Occupational status was closely associated with HBsAb and HBeAb serostatus (P < 0.001 and P = 0.039, respectively). Medical workers had the highest HBsAb seroprotection rate (82.03%), followed by teachers (71.17%), whereas farmers had the lowest HBsAb positivity (45.38%). For HBeAb positivity, farmers showed the highest rate (25.38%), followed by public institution staff (18.18%), while other occupational groups had the lowest prevalence (10.90%) (Table 3).

Educational attainment significantly affected the seroprevalence of HBsAg, HBeAg, and HBcAb (all P < 0.001). Higher educational level was correlated with increased HBsAb positivity and decreased HBeAb and HBcAb positivity, indicating better immune protection and lower historical infection exposure among more educated women. No significant differences in any of the five HBV markers were detected across different ethnic groups (P > 0.05). Household per capita monthly income only influenced HBsAb seropositivity (P = 0.007), with no significant associations observed for the remaining four HBV serological indicators (P > 0.05) (Table 3).

3.3.3. Serological Profiles Stratified by Vaccination History, Obstetric History and Comorbidities

Vaccination status strongly correlated with HBV serological outcomes. Participants were grouped according to vaccination records: no immunization history, vaccination interval < 5 years, vaccination interval ≥ 5 years, and unclear vaccination history. The corresponding HBsAg positive rates were 13.50%, 0.94%, 4.30%, and 12.15%; HBsAb positive rates were 46.84%, 95.28%, 63.40%, and 46.96%; HBeAg positive rates were 4.22%, 0%, 0.86%, and 2.10%; HBeAb positive rates were 21.52%, 5.66%, 14.35%, and 17.76%; and HBcAb positive rates were 37.55%, 13.21%, 33.028%, and 35.3%, respectively. All differences were statistically significant (all P < 0.001). Participants with no or unclear vaccination history presented substantially higher rates of HBV infection markers and insufficient antibody protection. Moreover, individuals with longer vaccination intervals (≥ 5 years) had poorer serological profiles than those vaccinated within five years, confirming progressive antibody attenuation and elevated infection risk over time (Table 3).

In terms of obstetric parity, HBeAb and HBcAb seropositivity increased significantly with higher parity (both P < 0.001). The positive rates of HBeAb were 13.33%, 13.76%, and 21.98%, and HBcAb positive rates were 27.49%, 32.92%, and 43.30% for primiparous, second-parity, and multiparous women (≥ 3 parity), respectively. No significant parity-related differences were found for HBsAg, HBsAb, and HBeAg (P > 0.05) (Table 3).

The presence of comorbidities markedly aggravated HBV infection risk. Women with underlying diseases exhibited significantly higher positive rates of HBsAg (38.30% vs. 6.20%), HBeAg (12.77% vs. 1.22%), HBeAb (34.04% vs. 15.04%), and HBcAb (63.83% vs. 32.26%), but a lower HBsAb positive rate (42.55% vs. 59.90%) compared with those without underlying diseases. These disparities were all statistically significant (all P < 0.001) (Table 3).

3.3.4. Serological Profiles Stratified by HBV Exposure History

Exposure risk factors further modulated HBV serostatus. The positivity rates of HBsAg and HBeAb were significantly higher in pregnant women with a history of sharing syringes compared to those without such a history, with statistically significant differences (P < 0.001 and P = 0.027). The positivity rates of HBsAg, HBeAg, HBeAb, and HBcAb were markedly higher among individuals living near hepatitis B patients or carriers than among those without such exposure, also showing statistically significant differences (P <0.001). No statistically significant differences were observed in the positivity rates of the five serum markers between individuals with or without a history of surgery, blood transfusion, acupuncture treatment, or shared daily utensils (P> 0.05) (Table 3).

3.4. Influencing Factors for HBsAg, HBsAb and HBcAb Positivity

3.4.1. Factors Associated with HBsAg Positivity

Multivariate logistic regression analysis demonstrated that advanced age and rural residence were independent risk factors for HBsAg positivity, while the absence of chronic comorbidities, hepatitis B vaccination history, and no surrounding HBV infection exposure were independent protective factors. Compared with the 14– year group, the 30–, 35–, and 40– year groups presented significantly higher HBsAg positivity risks, with ORs (95% CIs) of 5.01 (1.97–12.79), 5.65 (2.15–14.81), and 7.85 (2.64–23.33), respectively. Rural residence was associated with a higher risk relative to urban residence (OR = 2.27, 95% CI: 1.24–4.14). Participants without chronic diseases had a significantly lower HBsAg-positive risk than those with comorbidities (OR = 0.12, 95% CI: 0.06–0.28). Compared with participants with no immunization history, individuals with vaccination intervals of <5 years and ≥5 years had lower HBsAg positivity, with ORs (95% CIs) of 0.04 (0.01–0.34) and 0.24 (0.14–0.41), respectively. Relative to participants with surrounding HBV exposure, those with no exposure or unclear exposure status showed reduced HBsAg risk, with ORs (95% CIs) of 0.12 (0.07–0.19) and 0.27 (0.15–0.46), respectively (Table 5).

3.4.2. Factors Associated with HBsAb Positivity

Multivariate logistic regression analysis revealed that advanced age, urban residence, higher educational level, medical occupation, absence of chronic comorbidities, and a valid hepatitis B vaccination history were identified as protective factors for HBsAb positivity. Compared with the 14– year group, the 25–, 30–, 35–, and 40– year groups had higher probabilities of HBsAb seropositivity, with ORs (95% CIs) of 1.61 (1.16–2.23), 1.41 (1.00–1.97), 1.94 (1.34–2.81), and 2.48 (1.47–4.19), respectively. In comparison with urban residents, participants living in county-township and rural areas had lower HBsAb positivity, with ORs (95% CIs) of 0.70 (0.56–0.87) and 0.63 (0.46–0.86). Regarding educational level, participants with a bachelor’s degree and postgraduate education had higher HBsAb positivity than those with junior high school education or below, with ORs (95% CIs) of 1.54 (1.07–2.21) and 2.88 (1.01–8.21), respectively.

Taking medical staff as the reference group, personnel in public institutions, commercial service workers, factory workers, self-employed individuals, unemployed individuals, and farmers exhibited lower HBsAb positivity, with ORs (95% CIs) of 0.35 (0.17–0.70), 0.45 (0.24–0.84), 0.38 (0.16–0.87), 0.48 (0.28–0.83), 0.46 (0.24–0.87), and 0.32 (0.17–0.63), respectively. Participants without chronic comorbidities were more likely to be HBsAb-positive (OR = 2.27, 95% CI: 1.18–4.36) than those with underlying diseases. Compared with participants with no immunization history, those with vaccination intervals of <5 years and ≥5 years had significantly higher HBsAb positivity, with ORs (95% CIs) of 18.16 (7.03–46.89) and 1.64 (1.22–2.20) (Table 5).

3.4.3. Factors Associated with HBcAb Positivity

Multivariate logistic regression analysis indicated that advanced age was an independent risk factor for HBcAb positivity, while higher educational level, absence of chronic comorbidities, a short vaccination interval (<5 years), and no surrounding HBV exposure were protective factors. Compared with the 14-year group, the 25-, 30-, 35-, and 40-year groups showed progressively increased HBcAb-positive risks, with ORs (95% CIs) of 2.20 (1.41–3.42), 4.45 (2.87–6.92), 6.13 (3.86–9.71), and 12.48 (6.93–22.49), presenting a significant age-dependent rising trend. Participants with a bachelor’s degree and postgraduate education had lower HBcAb positivity than those with junior high school education or below, with ORs (95% CIs) of 0.63 (0.43–0.94) and 0.33 (0.12–0.86). The absence of chronic comorbidities reduced the HBcAb-positive risk (OR = 0.30, 95% CI: 0.15–0.58). Participants vaccinated within 5 years had a lower HBcAb positivity rate than those with no immunization history (OR = 0.23, 95% CI: 0.12–0.44). Relative to individuals with surrounding HBV exposure, those with no exposure or unclear exposure status had lower HBcAb positivity, with ORs (95% CIs) of 0.37 (0.27–0.51) and 0.45 (0.31–0.64), respectively (Table 5).

Table 4. Variable Assignment Table for the Multivariate Logistic Regression Model.

variable	Value Explanation
Age (years)	14– years = 0; 25– years = 1; 30– years = 2; 35– years = 3; 40– years = 4
Residential area	Urban = 0, County/township = 1, Rural = 2
Occupation	Medical staff = 0; Teachers = 1; Enterprise employees = 2; Institutional staff = 3; Commercial service staff = 4; Workers = 5; Self-employed = 6; Housework/unemployed = 7; Farmers = 8; Others = 9
Educational	Junior high school or below = 0; High school or vocational school = 1; College diploma = 2; Bachelor’s degree = 3; Master’s degree or above = 4
Monthly household per capita income (CNY)	<2000= 0; 2000–4999 = 1; 5000–9999 = 2; ≥10000 = 3
Comorbidity	Yes = 0, No = 1
Vaccination history	No immunization history = 0; Immunization interval <5 years = 1; Immunization interval ≥ 5 years = 2; Immunization history unknown = 3
Number of pregnancies	1 birth = 0; 2 births = 1; 3 or more births = 2
History of sharing syringes	Yes = 0, No = 1, Unknown = 2
There are hepatitis B patients around me.	Yes = 0, No = 1, Unknown = 2

Table 4. Variable Assignment Table for the Multivariate Logistic Regression Model.

variable	Value Explanation
Age (years)	14– years = 0; 25– years = 1; 30– years = 2; 35– years = 3; 40– years = 4
Residential area	Urban = 0, County/township = 1, Rural = 2
Occupation	Medical staff = 0; Teachers = 1; Enterprise employees = 2; Institutional staff = 3; Commercial service staff = 4; Workers = 5; Self-employed = 6; Housework/unemployed = 7; Farmers = 8; Others = 9
Educational	Junior high school or below = 0; High school or vocational school = 1; College diploma = 2; Bachelor’s degree = 3; Master’s degree or above = 4
Monthly household per capita income (CNY)	<2000= 0; 2000–4999 = 1; 5000–9999 = 2; ≥10000 = 3
Comorbidity	Yes = 0, No = 1
Vaccination history	No immunization history = 0; Immunization interval <5 years = 1; Immunization interval ≥ 5 years = 2; Immunization history unknown = 3
Number of pregnancies	1 birth = 0; 2 births = 1; 3 or more births = 2
History of sharing syringes	Yes = 0, No = 1, Unknown = 2
There are hepatitis B patients around me.	Yes = 0, No = 1, Unknown = 2

Table 5. Multivariate Logistic Regression Analysis of the Distribution of Hepatitis B Serological Markers Among Pregnant Women in Nanning City (2024–2025).

variable	HBsAg					HBsAb					HBcAb
	β	S.E.	Wald χ2	p	OR (CI:95%)	β	S.E.	Wald χ2	p	OR (CI:95%)	β	S.E.	Wald χ2	p	OR (CI:95%)
Age (years)
14–	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
25–	0.752	0.495	1.52	0.128	2.12(0.8～5.59)	0.474	0.167	2.831	0.005	1.61(1.16～2.23)	0.787	0.226	3.488	<0.001	2.2(1.41～3.42)
30–	1.612	0.478	3.374	0.001	5.01(1.97～12.79)	0.34	0.172	1.973	0.048	1.41(1.0～1.97)	1.494	0.225	6.64	<0.001	4.45(2.87～6.92)
35–	1.732	0.492	3.521	<0.001	5.65(2.15～14.81)	0.664	0.189	3.52	<0.001	1.94(1.34～2.81)	1.813	0.235	7.709	<0.001	6.13(3.86～9.71)
40–	2.061	0.555	3.71	<0.001	7.85(2.64～23.33)	0.91	0.267	3.41	0.001	2.48(1.47～4.19)	2.525	0.3	8.408	<0.001	12.48(6.93～22.49)
Residential area
Urban	-	-	-	-	-	-	-	-	-	-		-	-	-	-
County/township	0.373	0.243	1.536	0.124	1.45(0.9～2.34)	-0.361	0.116	-3.118	0.002	0.7(0.56～0.87)		-	-	-	-
Rural	0.818	0.308	2.659	0.008	2.27(1.24～4.14)	-0.46	0.16	-2.885	0.004	0.63(0.46～0.86)		-	-	-	-
Occupation
Medical staff	-	-	-	-	-	-	-	-	-	-		-	-	-	-
Teacher	-	-	-	-	-	-0.518	0.333	-1.554	0.12	0.6(0.31～1.14)		-	-	-	-
Enterprise employees	-	-	-	-	-	-0.682	0.294	-2.325	0.02	0.51(0.28～0.9)		-	-	-	-
Institutional staff	-	-	-	-	-	-1.057	0.355	-2.977	0.003	0.35(0.17～0.7)		-	-	-	-
Commercial service staff	-	-	-	-	-	-0.794	0.314	-2.531	0.011	0.45(0.24～0.84)		-	-	-	-
worker	-	-	-	-	-	-0.973	0.426	-2.286	0.022	0.38(0.16～0.87)		-	-	-	-
Self-employed	-	-	-	-	-	-0.73	0.278	-2.623	0.009	0.48(0.28～0.83)		-	-	-	-
Housework/unemployed	-	-	-	-	-	-0.783	0.326	-2.403	0.016	0.46(0.24～0.87)		-	-	-	-
Farmer	-	-	-	-	-	-1.128	0.342	-3.299	0.001	0.32(0.17～0.63)		-	-	-	-
Other	-	-	-	-	-	-0.877	0.313	-2.799	0.005	0.42(0.23～0.77)		-	-	-	-
Educational
Junior high school and below	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
High school or vocational school	-	-	-	-	-	0.233	0.147	1.586	0.113	1.26(0.95～1.68)	-0.03	0.158	-0.188	0.851	0.97(0.71～1.32)
College diploma	-	-	-	-	-	0.068	0.153	0.444	0.657	1.07(0.79～1.44)	-0.289	0.168	-1.724	0.085	0.75(0.54～1.04)
Bachelor’s degree	-	-	-	-	-	0.43	0.186	2.317	0.021	1.54(1.07～2.21)	-0.456	0.2	-2.277	0.023	0.63(0.43～0.94)
Master’s degree and above	-	-	-	-	-	1.057	0.535	1.978	0.048	2.88(1.01～8.21)	-1.121	0.497	-2.257	0.024	0.33(0.12～0.86)
Monthly household per capita income (CNY)
<2000	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
2000～4999	-	-	-	-	-	0.15	0.132	1.134	0.257	1.16(0.9～1.51)	-	-	-	-	-
5000～9999	-	-	-	-	-	-0.102	0.169	-0.605	0.545	0.9(0.65～1.26)	-	-	-	-	-
≥10000	-	-	-	-	-	-0.325	0.262	-1.238	0.216	0.72(0.43～1.21)	-	-	-	-	-
Comorbidity
Yes	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
No	-2.09	0.412	-5.079	0	0.12(0.06～0.28)	0.821	0.333	2.465	0.014	2.27(1.18～4.36)	-1.206	0.338	-3.567	<0.001	0.3(0.15～0.58)
Vaccination history
No immunization history	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Interval <5 years	-3.158	1.061	-2.975	0.003	0.04(0.01～0.34)	2.899	0.484	5.991	<0.001	18.16(7.03～46.89)	-1.487	0.34	-4.374	<0.001	0.23(0.12～0.44)
Interval ≥5 years	-1.438	0.276	-5.211	0	0.24(0.14～0.41)	0.492	0.152	3.246	0.001	1.64(1.22～2.2)	-0.226	0.166	-1.361	0.174	0.8(0.58～1.1)
Unknown	-0.113	0.286	-0.396	0.692	0.89(0.51～1.56)	-0.079	0.172	-0.461	0.645	0.92(0.66～1.29)	-0.052	0.19	-0.273	0.785	0.95(0.65～1.38)
Number of pregnancies
1 birth	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
2 births	-	-	-	-	-	-	-	-	-	-	-0.027	0.129	-0.211	0.833	0.97 (0.76～1.25)
≥3 births	-	-	-	-	-	-	-	-	-	-	0.261	0.146	1.792	0.073	1.3(0.98～1.73)
History of sharing syringes
Yes	-	-	-	-	-						-	-	-	-	-
No	-1.171	0.881	-1.329	0.184	0.31(0.06～1.74)						-	-	-	-	-
Unknown	-0.719	0.954	-0.754	0.451	0.49(0.08～3.16)						-	-	-	-	-
HBV patients/infected persons around
Yes	-	-	-	-	-						-	-	-	-	-
No	-2.135	0.247	-8.658	<0.001	0.12(0.07～0.19)						-0.987	0.156	-6.331	<0.001	0.37(0.27～0.51)
Unknown	-1.32	0.282	-4.685	<0.001	0.27(0.15～0.46)						-0.809	0.183	-4.424	<0.001	0.45(0.31～0.64)

Table 5. Multivariate Logistic Regression Analysis of the Distribution of Hepatitis B Serological Markers Among Pregnant Women in Nanning City (2024–2025).

variable	HBsAg					HBsAb					HBcAb
	β	S.E.	Wald χ2	p	OR (CI:95%)	β	S.E.	Wald χ2	p	OR (CI:95%)	β	S.E.	Wald χ2	p	OR (CI:95%)
Age (years)
14–	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
25–	0.752	0.495	1.52	0.128	2.12(0.8～5.59)	0.474	0.167	2.831	0.005	1.61(1.16～2.23)	0.787	0.226	3.488	<0.001	2.2(1.41～3.42)
30–	1.612	0.478	3.374	0.001	5.01(1.97～12.79)	0.34	0.172	1.973	0.048	1.41(1.0～1.97)	1.494	0.225	6.64	<0.001	4.45(2.87～6.92)
35–	1.732	0.492	3.521	<0.001	5.65(2.15～14.81)	0.664	0.189	3.52	<0.001	1.94(1.34～2.81)	1.813	0.235	7.709	<0.001	6.13(3.86～9.71)
40–	2.061	0.555	3.71	<0.001	7.85(2.64～23.33)	0.91	0.267	3.41	0.001	2.48(1.47～4.19)	2.525	0.3	8.408	<0.001	12.48(6.93～22.49)
Residential area
Urban	-	-	-	-	-	-	-	-	-	-		-	-	-	-
County/township	0.373	0.243	1.536	0.124	1.45(0.9～2.34)	-0.361	0.116	-3.118	0.002	0.7(0.56～0.87)		-	-	-	-
Rural	0.818	0.308	2.659	0.008	2.27(1.24～4.14)	-0.46	0.16	-2.885	0.004	0.63(0.46～0.86)		-	-	-	-
Occupation
Medical staff	-	-	-	-	-	-	-	-	-	-		-	-	-	-
Teacher	-	-	-	-	-	-0.518	0.333	-1.554	0.12	0.6(0.31～1.14)		-	-	-	-
Enterprise employees	-	-	-	-	-	-0.682	0.294	-2.325	0.02	0.51(0.28～0.9)		-	-	-	-
Institutional staff	-	-	-	-	-	-1.057	0.355	-2.977	0.003	0.35(0.17～0.7)		-	-	-	-
Commercial service staff	-	-	-	-	-	-0.794	0.314	-2.531	0.011	0.45(0.24～0.84)		-	-	-	-
worker	-	-	-	-	-	-0.973	0.426	-2.286	0.022	0.38(0.16～0.87)		-	-	-	-
Self-employed	-	-	-	-	-	-0.73	0.278	-2.623	0.009	0.48(0.28～0.83)		-	-	-	-
Housework/unemployed	-	-	-	-	-	-0.783	0.326	-2.403	0.016	0.46(0.24～0.87)		-	-	-	-
Farmer	-	-	-	-	-	-1.128	0.342	-3.299	0.001	0.32(0.17～0.63)		-	-	-	-
Other	-	-	-	-	-	-0.877	0.313	-2.799	0.005	0.42(0.23～0.77)		-	-	-	-
Educational
Junior high school and below	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
High school or vocational school	-	-	-	-	-	0.233	0.147	1.586	0.113	1.26(0.95～1.68)	-0.03	0.158	-0.188	0.851	0.97(0.71～1.32)
College diploma	-	-	-	-	-	0.068	0.153	0.444	0.657	1.07(0.79～1.44)	-0.289	0.168	-1.724	0.085	0.75(0.54～1.04)
Bachelor’s degree	-	-	-	-	-	0.43	0.186	2.317	0.021	1.54(1.07～2.21)	-0.456	0.2	-2.277	0.023	0.63(0.43～0.94)
Master’s degree and above	-	-	-	-	-	1.057	0.535	1.978	0.048	2.88(1.01～8.21)	-1.121	0.497	-2.257	0.024	0.33(0.12～0.86)
Monthly household per capita income (CNY)
<2000	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
2000～4999	-	-	-	-	-	0.15	0.132	1.134	0.257	1.16(0.9～1.51)	-	-	-	-	-
5000～9999	-	-	-	-	-	-0.102	0.169	-0.605	0.545	0.9(0.65～1.26)	-	-	-	-	-
≥10000	-	-	-	-	-	-0.325	0.262	-1.238	0.216	0.72(0.43～1.21)	-	-	-	-	-
Comorbidity
Yes	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
No	-2.09	0.412	-5.079	0	0.12(0.06～0.28)	0.821	0.333	2.465	0.014	2.27(1.18～4.36)	-1.206	0.338	-3.567	<0.001	0.3(0.15～0.58)
Vaccination history
No immunization history	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Interval <5 years	-3.158	1.061	-2.975	0.003	0.04(0.01～0.34)	2.899	0.484	5.991	<0.001	18.16(7.03～46.89)	-1.487	0.34	-4.374	<0.001	0.23(0.12～0.44)
Interval ≥5 years	-1.438	0.276	-5.211	0	0.24(0.14～0.41)	0.492	0.152	3.246	0.001	1.64(1.22～2.2)	-0.226	0.166	-1.361	0.174	0.8(0.58～1.1)
Unknown	-0.113	0.286	-0.396	0.692	0.89(0.51～1.56)	-0.079	0.172	-0.461	0.645	0.92(0.66～1.29)	-0.052	0.19	-0.273	0.785	0.95(0.65～1.38)
Number of pregnancies
1 birth	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
2 births	-	-	-	-	-	-	-	-	-	-	-0.027	0.129	-0.211	0.833	0.97 (0.76～1.25)
≥3 births	-	-	-	-	-	-	-	-	-	-	0.261	0.146	1.792	0.073	1.3(0.98～1.73)
History of sharing syringes
Yes	-	-	-	-	-						-	-	-	-	-
No	-1.171	0.881	-1.329	0.184	0.31(0.06～1.74)						-	-	-	-	-
Unknown	-0.719	0.954	-0.754	0.451	0.49(0.08～3.16)						-	-	-	-	-
HBV patients/infected persons around
Yes	-	-	-	-	-						-	-	-	-	-
No	-2.135	0.247	-8.658	<0.001	0.12(0.07～0.19)						-0.987	0.156	-6.331	<0.001	0.37(0.27～0.51)
Unknown	-1.32	0.282	-4.685	<0.001	0.27(0.15～0.46)						-0.809	0.183	-4.424	<0.001	0.45(0.31～0.64)

3.5. Distribution of Serum HBsAb Concentrations

The geometric mean concentration (GMC) of HBsAb was analyzed among uninfected participants and those with previous/occult HBV infection. For the total 1800 eligible participants, the overall GMC of HBsAb was 11.22 ± 49.37 mIU/mL. Stratified by infection status, the GMC was 4.63 ± 54.21 mIU/mL among 1295 uninfected pregnant women and 16.79 ± 71.67 mIU/mL among 505 women with previous/occult HBV infection. Participants with previous or occult HBV infection exhibited a significantly higher HBsAb GMC than uninfected individuals (P < 0.001). Among uninfected pregnant women, the HBsAb GMC differed significantly across subgroups stratified by age, residential area, occupation, educational level, household per capita monthly income, vaccination history, parity, and surrounding HBV exposure status (all P < 0.05). In contrast, no significant differences in HBsAb GMC were observed regarding ethnicity, chronic comorbidities, surgical history, blood transfusion history, acupuncture history, syringe sharing, and shared daily necessities (all P > 0.05). For participants with previous/occult HBV infection, significant differences in HBsAb GMC were only found in subgroups stratified by age and household per capita monthly income (both P < 0.05) (Table 6).

4. Discussion

This cross-sectional study systematically analyzed the current epidemiological status, immune protection level, and associated influencing factors of HBV infection among pregnant women in Nanning from 2024 to 2025. The results revealed that the overall HBsAg positive rate among the enrolled pregnant women was 6.98%, which was higher than the national general population level of 5.86% reported in 2020 [12] and slightly higher than the national maternal HBsAg prevalence of 6.64% in 2024 [19]. Additionally, the prevalence observed in this study was markedly higher than that in pregnant populations from Jiangsu (2.74%), Xinjiang (2.36%), and Qingdao, Shandong (3.36%) [26,27], while lower than that in Quanzhou, Fujian (8.85%) [28]. Compared with the HBsAg positive rate of 9.84% among pregnant women in Guangxi in 2016, the prevalence in the present study decreased by 29.07%, which was consistent with the overall national declining trend during the same period [29]. These findings indicate that HBV prevention and control programs for pregnant women in Nanning have achieved preliminary effects. Nevertheless, the local HBV epidemic among childbearing women remains at a moderate-to-high endemic level, suggesting that the prevention and control situation is still severe.

Serological pattern analysis demonstrated that uninfected susceptible individuals, effectively immunized individuals, and HBV-infected individuals each accounted for approximately one-third of the pregnant population in Nanning, which was consistent with findings from previous domestic studies [30]. Age-stratified analysis showed that younger pregnant women were predominantly susceptible or immune-protected, whereas older participants had substantially higher proportions of previous/occult and current HBV infections. This age-specific distribution indicates a persistent reservoir of HBV infection among local pregnant women, leading to a potential high risk of mother-to-child transmission (MTCT) and posing a substantial challenge to China’s progress toward the WHO global goal of eliminating viral hepatitis.

This study found that HBV infection among pregnant women exhibits distinct age distribution patterns, with the HBsAg positivity rate gradually increasing with age—from 2.4% in those aged 14–24 to 15.1% in those aged 40–47. As age increases, the proportions of susceptible individuals and those with a history of immunity progressively decline, while the proportions of previously infected individuals and current infections continue to rise. Multivariate regression analysis confirmed that advanced age is a risk factor for HBsAg, HBsAb, and HBcAb positivity, consistent with findings from related domestic studies [7]. This is attributed not only to the natural decline of protective antibodies and the cumulative exposure to the virus but also closely linked to the implementation progress of China’s hepatitis B immunization program [7]. In this study, pregnant women under 25 years old were born after 2000; during this period, the Chinese government fully implemented the Expanded Program on Immunization (EPI), ensuring free hepatitis B vaccination for children, with a full vaccination rate exceeding 85% [10], effectively reducing HBV infection risks in this age group. In contrast, pregnant women aged 25 and above were predominantly born between 1980 and 2000, when the hepatitis B vaccine had just been introduced clinically and had not yet been widely incorporated into the national immunization program. Children in this group had to pay out-of-pocket for vaccination, resulting in low overall vaccination rates and limited active immune protection, with most obtaining immunity through natural infection. Additionally, this demographic exhibited broader social exposure and more pregnancies, further increasing HBV exposure risks [10], leading to a dual-high phenomenon in both HBV infection rates and HBsAb positivity rates among this birth cohort.

This study identified significant urban–rural disparities in HBV prevalence among pregnant women. The HBsAg-positive risk among rural pregnant women was 2.27 times that among urban residents, while their HBsAb positive rate was only 63% of the urban level. This spatial distribution pattern is consistent with the national and regional epidemiological characteristics of HBV in Guangxi [19,23,31]. The underlying reasons may involve uneven allocation of medical and health resources, inconsistent implementation of prenatal HBV screening, and disparities in vaccination coverage and health awareness between urban and rural populations. Notably, no significant ethnic differences were observed in HBV serological markers or protective antibody levels, indicating that traditional ethnic customs no longer serve as a major determinant of HBV infection among local pregnant women following the continuous integration of lifestyles across different ethnic groups. Among uninfected participants, medical workers and individuals with higher educational levels maintained higher HBsAb positive rates and stronger antibody protection. This phenomenon is likely attributed to their superior knowledge of HBV prevention, stronger health awareness, higher vaccination adherence, and more standardized booster immunization practices, which collectively sustain stable immune protection.

From the perspective of population immunity, the overall vaccination coverage and long-term immune maintenance among reproductive-age women in Nanning remain suboptimal. In the present cohort, only 65.54% of pregnant women had a documented hepatitis B vaccination history, and merely 5.48% completed vaccination within the past five years, suggesting insufficient primary vaccination coverage and inadequate recent booster immunization among local women of childbearing age. In terms of immune response quality, participants vaccinated within five years achieved an HBsAb seroconversion rate of 95% and a high geometric mean concentration (GMC) of 223.37 mIU/mL, indicating robust protective immunity. In contrast, unvaccinated participants had a seroconversion rate of only 46.8% and an extremely low HBsAb GMC of 1.21 mIU/mL, representing negligible immune protection. These results strongly verify that standardized hepatitis B vaccination effectively enhances immune protection in reproductive-age females. Among vaccinated individuals, those with an interval of ≥5 years since the last vaccination had a breakthrough infection rate of 4.3%, which was 4.78-fold higher than that in women vaccinated within five years. Most breakthrough infections occurred in participants over 25 years of age with a vaccination interval exceeding 20 years. Accumulated evidence indicates that fully vaccinated immunocompetent individuals can maintain protective immunity for approximately 20 years, but antibody titers decline continuously over time, and childhood vaccination induces faster antibody attenuation, which frequently drops below the protective threshold of 10 mIU/mL in adulthood [7]. Accordingly, prolonged protective antibody attenuation is a significant factor contributing to breakthrough infections among older pregnant women. As the most cost-effective strategy to prevent maternal HBV infection and block MTCT, Standardized hepatitis B vaccination is strongly recommended by domestic expert consensus for timely booster immunization among individuals with HBsAb titers < 10 mIU/mL, so as to consolidate population immune barriers [32].

This study also identified that pregnant women with chronic underlying diseases or a history of close HBV exposure were high-risk populations for HBV infection. Existing studies have demonstrated that comorbid HBV infection can exacerbate pre-existing chronic conditions and significantly increase the long-term risks of liver cirrhosis and hepatocellular carcinoma. For instance, patients with concurrent diabetes and HBV infection have a 2–3 fold higher risk of severe liver injury, cirrhosis, and primary liver cancer compared with the general population [33]. Therefore, targeted strategies focusing on high-risk pregnant women with underlying diseases or definite HBV exposure are urgently required, including rigorous pre-pregnancy and prenatal HBV serological screening, timely vaccination for susceptible individuals, and standardized follow-up and treatment for confirmed HBV cases to minimize new infections and MTCT risks.

Several limitations of this study should be acknowledged. First, as a cross-sectional investigation, this study can only demonstrate associations between demographic and clinical factors and HBV infection or antibody levels, rather than confirming causal relationships. Second, vaccination history was partially collected through retrospective self-report, which may introduce recall bias and minor result deviations. Third, participants were recruited from partial medical institutions in Nanning, which may limit the generalizability of the findings to other regions.

Several limitations of this study should be acknowledged. First, this study was a cross-sectional survey, which only allowed the analysis of associations between various factors and HBV infection status as well as antibody levels, rather than verifying causal relationships between variables. Second, the vaccination history of some participants was collected via retrospective inquiry, which may lead to recall bias. Additionally, this study failed to collect data on vaccination intervals longer than five years, limiting the observation of long-term immune persistence and potentially causing minor deviations in the results. Third, participants were enrolled from only partial medical institutions in Nanning, which restricted the sample representativeness. Therefore, caution should be exercised when generalizing the conclusions to other regions.

In conclusion, the HBV infection prevalence among pregnant women in Nanning is relatively higher than the national average, and the current prevention and control system still has prominent deficiencies, including significant urban–rural disparities in endemicity, elevated infection risks among older pregnant women and those with chronic comorbidities, insufficient population vaccination coverage, and widespread long-term antibody attenuation. Based on these findings, targeted optimization of local HBV prevention strategies is warranted. Priority should be given to strengthening health management and HBV intervention for rural residents, older pregnant women, and individuals with underlying diseases. We recommend incorporating routine HBsAb detection into pre-pregnancy screening programs and implementing timely supplementary and booster vaccination for women with insufficient antibody levels before and during pregnancy. These targeted measures will help improve the immune barrier among reproductive-age females, reduce regional HBV incidence, and ultimately decrease the occurrence of HBV MTCT.

Current hepatitis B prevention and control efforts still face significant challenges, as evidenced by the relatively higher HBV prevalence among pregnant women in Nanning compared with the national level. The local HBV epidemic presents prominent public health gaps, including remarkable urban–rural disparities in infection distribution, disproportionately high infection risks among older pregnant women and those with chronic comorbidities, inadequate vaccination coverage among reproductive-age females, and widespread long-term attenuation of protective HBsAb antibodies. In view of these findings, targeted and refined HBV prevention strategies are urgently needed to improve maternal HBV health management. Priority interventions should focus on high-risk groups, including rural populations, elderly childbearing women, and individuals with underlying chronic diseases, to strengthen targeted screening and standardized health interventions. Furthermore, integrating routine HBsAb detection into pre-pregnancy health screening is strongly recommended, and timely supplementary and booster vaccination should be implemented for women with insufficient protective antibody levels before and during pregnancy.

These targeted population-based interventions are highly consistent with the core recommendations of the 2024 WHO guidelines for chronic hepatitis B prevention and management, which advocate expanded screening strategies, optimized vaccination interventions, and enhanced mother-to-child transmission prophylaxis for pregnant women [34]. As emphasized in the 2024 WHO Global Hepatitis Report, low- and middle-income countries still face substantial barriers to universal screening, vaccination coverage, and standardized health management for viral hepatitis, and precise intervention targeting key susceptible populations is critical to accelerating hepatitis B elimination progress [35]. Collectively, the findings of this study provide localized epidemiological evidence and practical intervention references for optimizing regional maternal HBV prevention and control systems, which can help narrow the urban–rural epidemic gap, consolidate population immune barriers among reproductive-age women, reduce indigenous HBV infection incidence, and ultimately promote the achievement of WHO global hepatitis B elimination targets.