The management of hepatitis B virus (HBV) infection in pregnancy is complex. Because infection with HBV in infancy often leads to chronic disease, prevention of perinatal or vertical transmission is a major goal. Worldwide, vertical transmission remains the most frequent route of infection, particularly in endemic areas where up to 20% of women of childbearing age may have HBV. These women constitute a reservoir for perinatal transmission, which is associated with a very high rate of chronicity [1–3]. Without immunoprophylaxis, up to 90% of infants born to hepatitis B e antigen (HBeAg)-positive mothers become HBV chronically infected. However, the maternal screening programs and universal vaccination in newborns with active and passive immunoprophylaxis have dramatically reduced HBV transmission rates. But even with the use of appropriate prophylaxis with HBV immunoglobulin (HBIG) and HBV vaccination, a significant risk of vertical transmission remains, particularly in mothers with high viral loads and positive hepatitis B e antigen (HBeAg) status. In one series of mothers with high viral loads, this risk was as high as 28% [4]. An HBV DNA level greater than 10 copies/ml is an important risk factor for HBV transmission [5,6]. Wiseman et al. [7] recently studied 298 chronically HBVinfected women and their infants, who were vaccinated and who received HBIG. The infants were tested for HBV at 9 months of age and showed an HBV rate of 8.5% born to mothers with virus levels greater than 8 log10 copies/ml. There is no indication to perform a caesarian section to reduce HBV transmission if vaccination and HBIG are administered accordingly. Factors that influence treatment choices in women of childbearing age include safety in pregnancy and breastfeeding, efficacy of the agent, its barrier to resistance, length of therapy, and most important, the cause of treatment, i.e. treating the mother because of an advanced liver disease or treating the unborn child to prevent transmission. If pregnancy is contemplated in near future, it may be prudent to delay therapy until after the child is born. This approach requires a careful assessment of the degree of hepatic activity and fibrosis. Although it is not to be used in the pregnant woman, interferon can be used in the woman of childbearing age, because therapy with this agent is for a defined period of 48 weeks and