A high maternal viral load is the most important factor affecting immunoprophylaxis against mother-infant transmission of HBV. The application of antiviral drugs in pregnant women with a high serum HBV DNA level (>10(6)~10(7) IU/ml) during the second and third trimesters can reduce the prenatal serum HBV DNA level and significantly increase the success rate of blocking mother-infant transmission in neonates. This article interprets the contents related to antiviral therapy for pregnant women carrying HBV with the purpose of blocking mother-infant transmission of HBV in the guidelines published by Asian Pacific Association for the Study of the Liver, European Association for the Study of the Liver, National Institute for Health and Care Excellence, Korean Association for the Study of the Liver, and World Health Organization.