WHO gives a positive answer on whether HBV-infected mothers can breastfeed, and there is no experimental evidence that breastfeeding leads to vertical transmission. On the contrary, breast milk contains a variety of proteins with different biological effects such as lactoferrin, which have antiviral activity against HCV, adenovirus, HIV, herpes simplex virus, rotavirus and cytomegalovirus. The AAP (American Academy of Pediatrics) recommends that breastfeeding by HBV-infected mothers is not contraindicated for infants receiving HBIG and HBV vaccine. Also, breastfeeding does not affect the immune response to hepatitis B vaccine. In one study enrolling 230 infants, 80.9% of those who received only hepatitis B vaccination developed surface antibodies at 1 year of age, and 73.2% of those who were artificially fed developed surface antibodies; for infants who received both hepatitis B vaccine and HBIG, the rates were 90.9% and 90.3% for those who were breastfed and artificially fed, respectively. Of course, breastfeeding women taking oral nucleoside (acid) antivirals are advised not to breastfeed because the safety of drug concentrations in breast milk for infants has not been adequately studied. Whether nucleoside (acid) analogs should be used to block mother-to-child transmission of HBV and reduce HBV DNA levels must take into account the potential risks. In general, the risks are greater in early pregnancy than in mid- to late pregnancy, the benefits of treatment during hepatitis episodes are greater than prevention by blocking HBV transmission from mother to child alone, and the safety of class B drugs in pregnancy may be greater than class C drugs in pregnancy. In clinical practice, female patients of childbearing age using such drugs should be advised to use reliable contraception, and pregnant patients with indications for antiviral therapy may choose drugs with a higher safety profile when the benefits outweigh the risks on balance, and avoid using such drugs for the sole purpose of preventing mother-to-child transmission of HBV. In the future, as more clinical studies of this type are conducted, the assessment of the safety of antiviral therapy in the reproductive years will become more standardized and reliable.