Factors associated with adverse perinatal outcomes among HBsAg-positive pregnant women in China: a retrospective cohort study

This study aimed to investigate the incidence of and explore risk factors for preterm birth (PB), low birth weight (LBW), and small for gestational age (SGA) among hepatitis B surface antigen (HBsAg)-positive pregnant women.
This study conducted a retrospective analysis of data from 53,150 HBsAg-positive pregnant women reported in the Henan’s information system for the management of mother-to-child transmission prevention of HBV between January 2021 and February 2022. Chi-square analysis, multivariate logistic regression analysis, and a Chi-square automatic interaction detector (CHAID) decision tree model were employed to investigate factors.
The incidence rates of PB, LBW, and SGA were 5.63%, 3.16%, and 5.16%, respectively. Multivariate logistic regression analysis revealed that maternal age of 20–30 years, a higher education level, and a female infants were protective factors against PB, whereas floating population and a gravidity greater than 1 were risk factors. For LBW, a higher education level was protective, while a female infant was a risk factor. Regrading SGA, higher education levels, gravidity > 1, parity > 1 were identified as protective factors, whereas HBV DNA ≥2 × 105 or HBeAg positive and antiviral therapy were risk factors. The CHAID model identified the sets of factors associated with each outcome.
This study found that the key modifiable risk factors included high viral load and lower education levels, while higher education and multiparity were protective. These findings support implementing targeted interventions such as enhanced prenatal monitoring for women with high viral load and health education programs for specific groups to mitigate adverse perinatal outcomes.