Abstract
A 33-year-old Japanese woman had a high hepatitis B virus (HBV) titer and was followed as an asymptomatic carrier. Her HBs antigen and HBe antigen were both positive and her viral load was 9.1 log copies/ml. Her first daughter became HBs antigen-positive at 6 months, even though she had received HB immunoglobulin at birth and 2 months and HB vaccines at 2, 3, and 5 months. To prevent mother-to-child infection of HBV in her second pregnancy, the mother was treated by lamivudine starting at 28 weeks of gestation. The mother's viral load decreased to 6.3 log copies/ml at delivery. Lamivudine treatment was stopped 3 months after delivery. After stopping lamivudine, her viral load increased to 9.1 log copies/ml. The mother had no transaminase elevation before and after antiviral therapy. Her second daughter had HB immunoglobulin and HB vaccines regularly, and her HBs antigen was negative at 1 year of age.