Background: Chronic hepatitis B virus (HBV) infection remains a key public health problem. In China, mother-to-child transmission is recognized as the major transmission pathway. The exact mechanism by which HBV enters the fetus through the maternal placenta is unclear, hampering the development of preventative interventions.
Objective: We aimed to identify perinatal factors influencing intrauterine transmission as determined by hepatitis B surface antigen (HBsAg) positivity 12 h after birth.
Study design: A total of 343 HBsAg(+) newborns with HBV(+) mothers were included in this study. The maternal marker expression pattern as well as associations of maternal HBsAg status with multiple perinatal risk factors for transmission (including sex, fetal position, mode of delivery, gestational age, number of complications, and infant HBV marker levels were analyzed.
Results: The majority of HBsAg(+) newborns were also HBeAg(+). The HBeAg and anti-HBe titers were significant higher in newborns from HBsAg(+) mothers than HBsAg(-) mothers (P=0.000). The frequency of ≥ 2 complications was significant higher in HBsAg(+) mothers than HBsAg(-) mothers (p=0.023). There was no significant difference in offspring in sex, mode of delivery, in utero position, or gestational age between HBsAg(+) and HBsAg(-) mothers (all P ≥ 0.05).
Conclusion: The HBsAg(+) newborns of HBsAg(+) mothers showed higher HBV viral replication rates than those of HBsAg(-) mothers. Maternal HBsAg-positivity and multiple pregnancy complications were significant risk factors for uterine mother-to-child HBV transmission. Offspring of HBV-infected mothers should be screened regularly for HBV markers to identify carriers.