Abstract: Objective The aim of this study was to compare the efficacy of telbivudine (LdT) and tenofovir disoproxil fumarate (TDF) in blocking hepatitis B viral transmission from mother to infant in pregnant women with high serum hepatitis B virus (HBV) deoxyribonucleic acid (DNA) loads. Methods 85 pregnant female HBV carriers with serum HBV DNA >1×10⁶ IU/mL were recruited in this study, and randomly divided into two groups, receiving LdT (n=43) or TDF (n=42) at gestational 28 weeks. The antiviral regimen lasted to the delivery. Serum HBV DNA and/or HBsAg positive were defined as HBV infection. Results At the delivery, serum HBV DNA load and HBeAg level in LdT-treated women were (2.9±0.6)lg IU/mL and (939.5±286.6)S/CO, both not significantly different compared to 【(3.1±0.7)lg IU/mL and (940.7±285.6)S/CO, respectively, P>0.05】 in TDF-treated women, and serum HBsAg, ALT and AST levels in the two groups were not much different (P>0.05); in LdT group, the infant's gestational age was (39.4±1.2)w, the height was (50.9±2.8)cm, the head circumference was(33.8±1.3)cm, the body mass was (3087.9±471.5)g and the Apgar score at one minute was(9.5±0.4), all not significantly different compared to【(39.6±1.1)w, (51.2±3.1)cm, (33.9±1.5)cm, (3112.9±464.9)g and (9.6±0.6), respectively, P>0.05】 in TDF group; the infant's HBV infection was 2.3% vs. 2.4% in the two groups (P>0.05). Conclusion Both LdT and TDF could be orally given to pregnant women with high serum HBV DNA loads at gestation of greater than 28 weeks to block mother-to-child HBV transmission, and worth further clinical investigation.

Key words: Hepatitis B viral carriers, Pregnancy, Mother-to-child transmission, Telbivudine, Tenofovir disoproxil fumarate