We conducted a study at the prenatal diagnosis center of Taizhou City. Fetuses with one or both parents carrying the hepatitis B surface antigen (HBsAg) were identified before genetic testing during the period 2008-2010. Intrauterine samples were obtained by amniocentesis or cordocentesis and tested for serological markers and by quantitative DNA assays. All neonates received combined hepatitis B immunoprophylaxis after delivery, and serological follow-up tests were performed at 1 year of age.