Mother-to-child transmission is the transmission of hepatitis B virus from a person with hepatitis B or a mother who is positive for hepatitis B virus surface antigen to her baby. According to statistics, 40% to 50% of HBsAg carriers in the population are due to mother-to-child transmission. The process of mother-to-child transmission of hepatitis B can be divided into three stages: 1. intrauterine transmission, that is, the transmission of hepatitis B virus from the mother’s blood to the baby via the placenta during pregnancy, which causes 5-10% of the transmission and cannot be prevented by the hepatitis B vaccine. 2, the transmission during delivery, that is, during the delivery of the baby, the baby’s skin abrasion, placental abruption, the virus in the mother’s blood through the ruptured placental vessels into the umbilical cord blood, or through the infection of the baby’s conjunctiva, into the body of the newborn; or the newborn contact or inhalation of maternal blood, amniotic fluid or vaginal secretions containing hepatitis B virus caused HBV infection; mother-to-child transmission of infection during delivery is the most likely, perinatal The transmission rate is estimated to be over 80%, and the first dose of hepatitis B vaccine and hepatitis B immunoglobulin (HBIG) within 24 hours after birth can prevent transmission during labor; 3. The rate of mother-to-child transmission is 40-50% in HBsAg-positive mothers, and 80%-90% in HBsAg- and HBeAg-dual-positive mothers. The combined prevention of HBIG and hepatitis B vaccine at birth can stop most mother-to-child HBV transmission, and the current rate of HBV infection in children has dropped to less than 5%.