After a pregnant woman has hepatitis B, the hepatitis B virus can enter the fetus through the placenta, and can also be transmitted to the baby through the birth canal and amniotic fluid contamination, etc. Close contact between mother and baby within 1 year after delivery also provides opportunities for transmission. According to statistics, the rate of hepatitis B virus carriage in pregnant women is 5-10%, and if no measures are taken, the rate of mother-to-child transmission is 20-50%, and if the mother is positive for hepatitis B e antigen, the transmission rate can reach 75-93%. Because the immune system of infants and children is not yet mature, once infected, they are prone to become asymptomatic carriers of hepatitis B virus or turn into chronic hepatitis. The best way to avoid transmitting the hepatitis B virus to infants is to give newborns the hepatitis B vaccine and hepatitis B immunoglobulin. The protection rate for blocking mother-to-child transmission with the hepatitis B vaccine alone is 87.8 percent. For newborns of HBsAg-positive mothers, 10 μg of yeast hepatitis B vaccine should be administered as early as possible within 24 h of birth, along with hepatitis B immune globulin (HBIG) at different sites (preferably within 12 h of birth, at a dose of ≥100 IU), which significantly improves the effectiveness of blocking mother-to-child transmission (about 93%). It is also possible to administer 1 dose of HBIG within 12 h of birth, followed by a second dose of HBIG 1 month later, along with 10 μg of hepatitis B vaccine, and 10 μg of hepatitis B vaccine 1 and 6 months apart, respectively. the latter is less convenient than the former, but its protection rate is higher than the former (>95%). Newborns can be breastfed by HBsAg-positive mothers after receiving hepatitis B vaccine and HBIG within 12 h of birth. The above two methods can effectively prevent the transmission of hepatitis B virus to the fetus through the placenta during labor and delivery of the pregnant woman and during close mother-infant contact after delivery. Therefore, pregnant women should pay attention to gentle movements, emotional stability and prohibition of conjugal life during pregnancy to avoid placental breakage. Some experts suggest that pregnant women should be given one injection of HBIG every month for 3 months before delivery, for a total of 3 injections until the delivery, or it can be reinforced once more 1 week before delivery. It should reduce the rate of hepatitis B virus infection, but the actual effect is not obvious and has been controversial. At present, there are more data at home and abroad to prove that if the level of hepatitis B virus can be consistently reduced to 10*6 during pregnancy, the rate of mother-to-child transmission is greatly reduced. Lamivudine and telbivudine are safer to use during pregnancy and have rapid antiviral effects, and can be used in the middle and late stages of pregnancy according to specific circumstances, but because the instructions of the two drugs have not yet indicated that they can be used in pregnancy, pregnant women should weigh the pros and cons and decide whether to use them. Patients with acute phase of viral hepatitis and hepatic cirrhosis should not risk pregnancy and childbirth. If a patient with hepatitis has normal liver function and cirrhosis is stable, she can have children under the guidance of a doctor. However, after pregnancy, it is necessary to check liver function regularly, increase nutrition and pay attention to rest appropriately. Pregnancy is not possible in decompensated cirrhosis. Since breast milk is not the main way to transmit hepatitis B virus and its risk is still less than blood transmission, breastfeeding is still possible if the baby is vaccinated with HBIG and hepatitis B vaccine. However, it is important to ensure that the nipples are clean and unbroken, the mammary glands are not inflamed, and the infant’s mouth is free of ulcers, etc. After the hepatitis B vaccination, the infant should be checked for surface antibodies to the hepatitis B virus as required by the physician, and if not, the hepatitis B vaccine should be given retroactively. 7 months of age is when the hepatitis B antibody titer can be checked. If the antibody titer is less than 10 mIU/ml, the baby should receive a booster shot of hepatitis B vaccine.