Infant characteristics of 183 children of 183 mother with CHB: Average birth weight was 3019 + 298.2 gram; the percentage of male and female were not significantly different (51.9% và 48.1%); the 18 percentage of vaginal delivery were higher than C-section (65.6% so với 34.4%) and almost 50.0% infants were exclusive breastfed (Table 3.4).