Hepatitis in pregnancy.

Currently, six distinct types of hepatitis virus have been identified: A, B, C, D, E, and G. Hepatitis A virus infection does not cause a chronic carrier state, and perinatal transmission is extremely uncommon. Hepatitis B can be transmitted perinatally, but immunization of the newborn with hepatitis B immune globulin and hepatitis B vaccine markedly reduces the risk of neonatal infection. Hepatitis D virus is dependent on coinfection with the hepatitis B virus for replication. Immunoprophylaxis against hepatitis B also is effective against hepatitis D. Hepatitis C virus is primarily transmitted by the parenteral route and is particularly likely to cause chronic liver disease. Perinatal transmission of hepatitis C principally occurs in women who have high titers of HCV-RNA or who are coinfected with human immunodeficiency virus. At this time, no immunoprophylaxis for hepatitis C is available. Hepatitis G, a recently described organism, is related to hepatitis C. Its clinical significance remains undetermined. Hepatitis E is transmitted in a manner similar to hepatitis A. Perinatal transmission is unusual, but maternal disease is often severe.