Prevention of vertical hepatitis B transmission by hepatitis B immunoglobulin in the third trimester of pregnancy.

OBJECTIVE: To explore the possible efficacy of using hepatitis B immunoglobulin (HBIG) during the third trimester of pregnancy to prevent intrauterine transmission of hepatitis B virus (HBV). METHODS: Of 469 pregnant women testing positive for hepatitis B surface antigens (HBsAg), 126 had hepatitis B e antigen (HBeAg) and 343 did not. RESULTS: There were women who declined to be treated with HBIG in these 2 groups. Among infants born to HBeAg-positive mothers, the rates of those testing positive for HBsAg at birth and at the 6-month visit were significantly lower when the mothers had been treated with HBIG (P<0.05). Among infants born to HBeAg-negative mothers, however, no significant differences were found whether the mothers had been treated or not. Furthermore, all newborns received HBIG treatment and the first dose of a vaccination schedule within 12 h of birth. At the 6-month visit the protective anti-HBs rates were only 32.3% among infants whose mothers were HBeAg-positive and 56.2% among those whose mothers were HBeAg-negative when their mothers had not been treated with HBIG during pregnancy, whereas the corresponding rates were as high as 75.8% and 88.7% when the mothers had been treated. CONCLUSION: Maternal administration of HBIG is effective in preventing intrauterine fetal HBV infection in HBsAg-positive, HBeAg-positive pregnant women and in improving immune response to hepatitis B vaccine in infants born to HBV carriers.