A pregnant woman with acute hepatitis B in whom vertical transmission was prevented by tenofovir disoproxil fumarate.

The optimal management of acute hepatitis B in pregnant women remains to be fully evaluated. A case of hepatitis B virus (HBV) infection in a 20-year-old pregnant woman who initially presented with jaundice is reported. Serum samples were positive for anti-HBc IgM and HBe antigen. Her husband was infected with HBV genotype A and received entecavir because of prolonged hepatitis and a high viral load. The HBV DNA sequence of the wife completely matched that of her husband, indicating that he was the source of HBV infection. In accordance with guidelines for the treatment of chronic HBV carriers, the wife started to receive tenofovir disoproxil fumarate (TDF) in her third trimester. After 4 months of treatment, the HBV DNA load decreased from 7.6 to 3.5 log copies/ml. At delivery, the serum was found negative for the HBe antigen. Seven months after treatment began, the HBs antigens also disappeared. The baby, totally healthy, received passive-active immunoprophylaxis. At 3 months, the baby remained free of HBV infection. TDF thus prevented exacerbation and prolongation of acute HBV infection in a pregnant woman. Subsequent treatment also prevented mother-to-infant transmission of HBV. The clinical course of her husband, who had HBV infection and received entecavir, is also reported.