Orally administered nucleus(t)ide analogues (NA) have brought about a simple, safe and effective therapeutic approach for chronic hepatitis B (CHB). However, treatment duration is long and some female patients become pregnant during treatment. In recent years, there have been gradually increasing reports on the safety of telbivudine (LdT) treatment for chronic hepatitis B virus (HBV) infection in the third trimester of pregnancy to block mother-to-infant transmission (MTIT) of HBV; however, the safety of LdT treatment for chronic HBV infection for the entire pregnancy has not been reported. The aim of the present study was to evaluate the safety of LdT treatment for chronic HBV infection for the entire pregnancy and provide a reference for HBV-infected fertile women on how to block MTIT of HBV. Eighty-six pregnant women who received LdT treatment either before or in early pregnancy were enrolled in the study. Adverse events were prospectively observed for the entire pregnancy and perinatal period, and short-term and long-term follow-up of infants was conducted, monitoring the abnormalities of infants and blocking rate of MTIT with LdT treatment. Eighty-six pregnant women treated with LdT had a total of 89 pregnancies: 6 (6.7%) had early embryonic death or spontaneous abortion, 1 (1.1%) had ectopic pregnancy and three had a second pregnancy after initial abortion. Fifty-one mothers completed pregnancy: one had induction of labour at 24 weeks of pregnancy for cleft lip and palate of the foetus and 50 delivered 52 full-term live infants. One infant had right ear accessories, and the total occurrence of congenital abnormality was 3.8%. Thirty-nine infants were followed up for more than 6 months and completed all examinations for MTIT. None of the infants were HBsAg positive, resulting in a 100% success rate of blocking MTIT. All mothers maintained good liver function during the third trimester of pregnancy; 86% maintained complete virological response (HBV DNA <500 copies/mL) prior to delivery, and none developed progression of liver disease. Factors leading to increased adverse effects and drug resistance were not found. LdT treatment is safe and effective in chronic HBV-infected pregnant mothers for the entire pregnancy.