In countries with a high prevalence of chronic hepatitis B, perinatal transmission from mother to infant accounts for the majority of cases of chronic hepatitis B. Passive-active immunoprophylaxis with hepatitis B immunoglobulin and hepatitis B vaccine at birth is 95% efficacious in reducing the risk of HBV transmission but is less effective in HBeAg-positive mothers with very high serum HBV DNA levels. In the last 4 weeks of pregnancy lamivudine may provide additional protection in pregnant women who have high-level viremia. Further studies are needed to evaluate the use of nucleos(t)ide analogues to treat chronic hepatitis B during pregnancy.
