Background and Aims:The perinatal transmission of hepatitis B virus (HBV) remains an important global health problem.Here,a systematic review and meta-analysis were conducted to evaluate the evidence regarding the efficacy and maternal/fetal safety of treating pregnant women with lamivudine,telbivudine (LdT),and tenofovir (TDF).Methods:A PubMed and Scopus search resulted in 1,076 records,which were reduced to 36,containing 7,717 pregnant women with chronic HBV infection and 7467 infants meeting the inclusion criteria.The latest search was in August 2019.Results:Treatment with LdT,but not lamivudine and TDF,could significantly reduce the hepatitis B virus surface antigen-positive rate (odds ratio (OR) =0.37) in infants;it also led to higher rates of hepatitis B e antigen loss (OR =12.14),hepatitis B e antigen seroconversion (OR =8.93),and alanine aminotransferase normalization in mothers (OR =1.49).Each of these treatments was able to significantly reduce HBV DNA positivity at birth (total OR =0.19) and mother-to-child-transmission of HBV (total OR =0.15),and to cause higher rates of HBV DNA suppression in mothers (total OR =25.53).However,nucleos(t)ide analogues might also be involved in creatine kinase elevation (total OR =7.48).In contrast,no significant association was found between nucleos(t)ide analogue therapy and preterm/premature births,congenital malformation,low birth weight,and abortion or fetal/infant death.The results suggested LdT's high capability of preventing mother-to-childtransmission.However,TDF failed to show significant associations to a reduced risk of mother-to-child-transmission,probably due to the low number of patients included.Conclusions:Although using either lamivudine,LdT,orTDF could lead to more favorable maternal/fetal outcomes,LdT seemed to show more potential in resolving certain infant-and maternal-related outcomes.More studies on the safety profile of such treatments are required.