Efficacy and safety of telbivudine in different trimesters of pregnancy with high viremia for interrupting perinatal transmission of hepatitis B virus

Aim: We aimed to investigate the efficacy and safety of telbivudine (LdT) on the intervention of mother-to-child transmission (MTCT) in different trimesters of pregnant women with high viral loads. Methods: In this prospective cohort study, 160 cases of mothers with high viral loads were included. Eighty-two subjects received 600mg/day LdT therapy. Fifty of them started LdT therapy before the third trimester of gestation, including 17 cases before pregnancy, nine and 24 cases in the first and second trimesters of pregnancy, respectively. The other 32 cases started LdT in the third trimester of gestation. Control pregnant women (78 cases) did not take LdT therapy. MTCT rate was determined by hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) DNA data of infants at the 51st week post-partum. Adverse events were also evaluated throughout the study. Results: One hundred and sixty infants were born from 160 pregnant women. Both LdT-treated groups displayed a marked decline in HBV DNA levels from the beginning to delivery. Positive rate of serum HBsAg in infants born from the above two groups of mothers were 0% and 3.1%, respectively, which was significantly lower than that in the untreated controls (24.4%). The incidence of detectable HBV DNA levels was significantly lower in infants born to LdT-treated mothers than in the controls (16.7%) at the 51st week post-partum. No infant had birth defects. No severe adverse event or complication were observed in LdT-treated mothers or infants followed until the 51st week post-partum. Conclusion: The earlier application of LdT during pregnancy, the better preventive effects it offered on MTCT.