OBJECTIVETo investigate the risk factors for mother-to-child transmission of hepatitis B virus (HBV) and the efficacy of hepatitis B immunoprophylaxis in children at high risk of hepatitis B.

METHODSA questionnaire survey was performed on 539 HBsAg-positive mothers and their 551 children (aged from 6 months to 5 years) at high risk of hepatitis B. Serum markers of hepatitis B in the children at high risk of hepatitis B were measured. Univariate logistic regression analysis was used to investigate the risk factors for mother-to-child transmission of HBV.

RESULTSThe rate of hepatitis B vaccination in the children at high risk of hepatitis B was 100%, and 96.6% received injections of hepatitis B vaccine and hepatitis B immunoglobulin (HBIG). The HBsAg positive rate showed no significant differences between different age groups. The HBsAb positive rate gradually decreased with the increasing age (P<0.01). The children born to HBsAg- and HBeAg-positive mothers had a significantly higher hepatitis B infection rate than those born to HBsAg-positive mothers (15.1% vs 0.2%; P<0.01). The high-risk children who received hepatitis B vaccination alone had a significantly higher hepatitis B infection rate than those who received both hepatitis B vaccine and HBIG injections (28.6% vs 2.8%; P<0.01).

CONCLUSIONSThe HBsAb positive rate gradually decreases with the increasing age in children at high risk of hepatitis B. Maternal HBsAg and HBeAg positivity and the absence of HBIG combined with hepatitis B vaccine injections for children at high risk of hepatitis B are the risk factors for mother-to-child transmission of HBV.