The rate of HBV transmission from mother to child after 18 LAM and TDF intervention in our study was very low, similar to many studies in this field in the world and in Vietnam: A controlled clinical trial of Zhang et al. (2014) was conducted on women with chronic HBV infection with HBV DNA> 10 copies / ml who were receiving lamivudine (n = 53) or telbivudine (n = 257) starting at 28 th - 30 th week of gestation.