Children born to mothers with hepatitis B do not necessarily develop hepatitis B. The mother-to-child transmission of acute hepatitis B depends mainly on the time of the mother’s hepatitis B. The infection rate of infants with the disease in the early and middle stages of pregnancy is about 6.2%, while the infection rate of infants with the disease in the late stages of pregnancy to 2 months after delivery is as high as 70%. The infection rate of infants of mothers with chronic hepatitis B in China is about 40% or more. The infection rate of children of HBeAg-positive mothers is high, while the infection rate of children of HBeAg-negative mothers is low.