Chronic hepatitis B infection in pregnancy.

There are no standard guidelines to follow when a patient with chronic hepatitis B infection becomes pregnant or desires pregnancy. Topics to consider include which patients to treat, when to start treatment, what treatment to use and when to stop treatment. Without any prophylaxis or antiviral therapy, a hepatitis B surface antigen and E antigen positive mother has up to a 90% likelihood of vertical transmission of hepatitis B virus (HBV) to child. Standard of care in the United States to prevent perinatal transmission consists of administration of hepatitis B immune globulin and HBV vaccination to the infant. The two strongest risk factors of mother to child transmission (MTCT) of HBV infection despite immunoprophylaxis are high maternal HBV viral load and high activity of viral replication. The goal is to prevent transmission of HBV at birth by decreasing viral load and/or decreasing activity of the virus. Although it is still somewhat controversial, most evidence shows that starting antivirals in the third trimester is effective in decreasing MTCT without affecting fetal development. There is a growing body of literature supporting the safety and efficacy of antiviral therapies to reduce MTCT of hepatitis B. There are no formal recommendations regarding which agent to choose. Tenofovir, lamivudine and telbivudine have all been proven efficacious in decreasing viral load at birth without known birth defects, but final decision of which antiviral medication to use will have to be determined by physician and patient. The antivirals may be discontinued immediately if patient is breastfeeding, or within first four weeks if infant is being formula fed.