Chronic hepatitis B (hepatitis B for short) is defined as a person who tests positive for the hepatitis B virus, has been ill for more than six months or has an unclear date of onset and has clinical manifestations of chronic hepatitis. The clinical manifestations are weakness, fear of food, nausea, abdominal distension, and pain in the liver area. The liver is large, moderately hard in texture, and has light pressure pain. Severe disease may be accompanied by chronic liver disease face, spider nevus, liver palm, splenomegaly, and liver function may be abnormal or persistently abnormal. According to the clinical manifestations, they are classified as mild, moderate and severe. Chronic hepatitis B carriers are those who test positive for hepatitis B virus, have no symptoms of chronic hepatitis, have no abnormalities in serum ALT and AST for more than 3 consecutive follow-ups within 1 year, and have normal liver histological examination. How to prevent mother-to-child transmission of hepatitis B? 1. Cut off the transmission route HBsAg-positive pregnant women should avoid amniocentesis and shorten the delivery time to ensure the integrity of the placenta and minimize the exposure of the newborn to maternal blood. 2.Protect the newborn (active and passive immunization) The blockage rate of mother-to-child transmission by hepatitis B vaccine alone is 87.8%. For newborns of HBsAg-positive mothers, hepatitis B immunoglobulin should be injected as early as possible within 24 hours (preferably 12 hours) after birth at a dose of ≥100 IU, while 10 μg of recombinant yeast or 20 μg of Chinese hamster oocyte hepatitis B vaccine should be administered at different sites, and the second and third doses of hepatitis B vaccine should be administered at 1 and 6 months of age respectively, which can significantly improve the effect of blocking mother-to-child transmission. The effect of mother-to-child transmission can be significantly improved. The newborn can also receive one dose of hepatitis B immunoglobulin within 12 hours of birth, followed by a second dose of hepatitis B immunoglobulin 1 month later, and a 10-μg recombinant yeast or 20-μg Chinese hamster oocyte hepatitis B vaccine at different sites, followed by a second and third dose of hepatitis B vaccine at intervals of 1 and 6 months, respectively. Newborns were allowed to receive breastfeeding from HBsAg-positive mothers after HBIG and hepatitis B vaccine were administered within 12 h of birth.