The widespread use of the hepatitis B vaccine in newborns has been a great achievement in preventing hepatitis B virus infection in newborns. However, in this seemingly simple process of vaccination, deviations in the timing and method of injection may result in the failure of the interruption of mother-to-child transmission of hepatitis B. Therefore, it is very necessary to update the concepts of doctors to further reduce the possibility of mother-to-child transmission. In order to block the mother-to-child transmission of hepatitis B, first of all, we should know the way of mother-to-child transmission. At present, it is believed that the way of mother-to-child transmission of hepatitis B may be infected during labor and delivery, infected in utero, and infected through the egg, so the blockage of hepatitis B is also considered from these aspects. I. Blocking the infection during labor and delivery “injection within 24 hours can be” is a misunderstanding, the earlier the better “immune globulin” at your own expense should also be played Infection during labor and delivery is the most important way of transmission. The strong contractions of the uterus during labor may push the mother’s blood into the blood of the newborn. Since the virus has just entered the newborn’s bloodstream, if hepatitis B immunoglobulin can be injected at this time, the hepatitis B virus in the newborn’s bloodstream can be neutralized immediately, and the newborn will not be infected. However, if the injection is given too late (e.g. several hours or even 20 hours later), the virus in the newborn’s blood has already entered the liver cells, and it is useless to inject hepatitis B immunoglobulin again. Therefore, the earlier the newborn is injected with hepatitis B immunoglobulin, the better. The idea that it is okay to give the injection within 24 hours is completely wrong. Regarding the prevention of infection during labor and delivery, the most important thing is to inject the newborn with Hepatitis B Immunoglobulin and Hepatitis B Vaccine. According to the current regulations, Hepatitis B vaccine is free of charge, while Hepatitis B immunoglobulin is self-funded. My personal view is to mobilize the family to give Hepatitis B immunoglobulin (HBIG) to the newborn as far as possible, because the protective effect of Hepatitis B vaccine alone will be effective at least half a month later, and it is difficult to rely on the Hepatitis B vaccine alone for prevention if the baby has already been infected in the course of delivery. Unless the mother’s HBVDNA remains negative throughout the pregnancy. In this case, it is possible to skip the HBIG injection. This is because the level of infectiousness of the mother is closely related to the amount of HBVDNA in her blood. As long as HBVDNA is positive, it is possible to infect the fetus, and the higher the titer, the more infectious it is. Second, the prevention of in utero infection “in utero infection time” is not conclusive “in utero transmission definition” standard is not uniform First of all, the time of in utero infection, many people now believe that mainly in the last 3 months of pregnancy, but some people through the study of induced abortion of the fetus However, by studying the livers of induced fetuses, it has been found that infection can occur early in pregnancy. This issue needs further study as it relates to when to start prevention. Secondly, the definition of in utero transmission is not standardized. Some people think that “positive umbilical cord blood or venous blood after birth” is intrauterine transmission; some people think that positive HBV markers in peripheral blood after birth and continuing until the first month of life is intrauterine transmission; some people think that “after HBIG+Hepatitis B vaccine prophylaxis after birth, and 6+ months of persistent HBsAg (+)” is intrauterine transmission. Some people think that only those who have been vaccinated with HBIG+Hepatitis B vaccine after birth and have persistent (+) HBsAg at 6+ months are considered intrauterine transmission. I think the last one is more appropriate. Because, only after HBIG + Hepatitis B vaccine prophylaxis is ineffective can we be sure that it is intrauterine transmission. I hope that we can adopt a uniform standard in future studies. The last one is the blockage of intrauterine transmission, at present, there are two main methods, one is to give the mother an injection of HBIG every month in the last 3 months of pregnancy, and then follow the routine prophylaxis after the birth of the baby, which is considered to be effective in many reports, but some people think that it is difficult to reduce the HBVDNA in the blood by injecting an injection of HBIG as there is so much HBsAg in the blood of the patient, so the issue needs further research as well. research. Another method is to use the nucleoside analog lamivudine for prevention. The application of lamivudine can indeed reduce HBVDNA in the mother’s blood and reduce the rate of HBsAg carriage in the newborn, and it is possible to prevent it completely if the application is started before pregnancy, and it is also possible to reduce the rate of infection in the newborn by applying it from the 28th week of pregnancy. Theoretically, the earlier the application, the better the results. According to current reports, no adverse effects have occurred in newborns. However, it must also be pointed out that lamivudine for the interruption of mother-to-child transmission has not yet been approved by the relevant authorities, so it is best not to advise pregnant women to use it, and they can be informed of this situation in truth and detail, and the decision to use it is entirely up to the pregnant woman and her family. In addition, theoretically, tibivudine may be safer than lamivudine in the prevention of mother-to-child transmission, because it has no adverse reaction to the fetus from animal experiments, so it belongs to the B grade of pregnancy drugs, while lamivudine belongs to the C grade, but unfortunately, so far, there is no report of clinical application.