Hepatitis B virus DNA can be detected in the sperm of men with hepatitis B. HBV enters the egg cell with the sperm and proliferates during the formation of the embryo, making the baby a hepatitis B patient or HBV carrier. This type of HBV transmission can be called vertical transmission from father to child. The chances of such father-to-child transmission are small, but it is difficult to interrupt. Close contact in daily life and sexual intercourse during pregnancy can cause the pregnant woman to be infected with HBV, which can then infect the baby through the father-mother-infant route, which is a form of indirect father-to-child transmission. At present, most of the father-to-infant transmission of hepatitis B is acquired through close contact, or because of close contact between the father and mother during the mother’s pregnancy, resulting in father-to-mother-to-infant transmission, but this is not true vertical transmission and can be avoided or interrupted. Fathers can also transmit hepatitis B by usual daily contact, and infants are vaccinated against hepatitis B within 24 hours of birth so that the chances of transmission by daily contact are greatly reduced. The following methods are used to block paternal-infant transmission: 1. Since vertical paternal-infant transmission occurs at the germ cell stage, the most effective method to block paternal-infant transmission of hepatitis B is preconception intervention. Hepatitis B screening should be performed prior to marriage, and active treatment should be provided for either sex with hepatitis B. And if the mother is successfully immunized against hepatitis B vaccine before pregnancy until antibodies appear, i.e. when HBsAb reaches 10mIU/ml or more, it can effectively protect the pregnant woman and the newborn and reduce the possibility of infection with hepatitis B virus. 2.If the pregnant woman does not have protective antibodies in her body, an intramuscular injection of 200 IU of human hepatitis B immunoglobulin every 4 weeks starting from 20 weeks of pregnancy can effectively prevent hepatitis B virus infection from the husband and reduce the chance of father-mother-infant transmission of hepatitis B virus. 3. If the father is a hepatitis B virus carrier or hepatitis B patient, the newborn should be injected with 100 IU of human specific hepatitis B immunoglobulin within 6 hours and/or 1 month after birth, respectively, and hepatitis B vaccine as required to better protect the newborn and reduce the risk of HBV infection.