AIM:To achieve an evidence-based conclusion regarding the safety and efficacy of telbivudine during pregnancy.METHODS:A pooled analysis of data from a literature search reported 1739 pregnancy outcomes(1673 live births)from 1725 non-overlapping pregnant women treated with telbivudine.The prevalence of live birth defects(3.6/1000)was similar to that of the nonantiviral controls(3.0/1000)and not increased as compared with overall prevalence(14.5 to 60/1000).No target organ toxicity was identified.The prevalence of spontaneous abortion in pregnant women treated with telbivudine(4.2/1000)was not increased compared with the overall prevalence(16/1000).The mother-to-child transmission rate was significantly reduced in pregnant women treated with telbivudine(0.70%)compared to those treated with the non-antiviral controls(11.9%;P<0.0001)or compared to the historical rates of hepatitis B virus(HBV)-infected population without antiviral treatment(10%-15%).RESULTS:Cumulatively 489 pregnancy cases have been reported in the telbivudine pharmacovigilance database(with a cut-off date 31 August 2014),of those,308 had known pregnancy outcomes with 249 cases of live births(239 cases of live birth without congenital anomaly and 10 cases of live birth with congenital anomaly).In the latest antiretroviral pregnancy registry report(1 January 1989 through 31 January 2015)of27 patients exposed to telbivudine during pregnancy(18,6 and 3 during first,second and third trimester,respectively)19 live births were reported and there were no cases of birth defects reported.CONCLUSION:Telbivudine treatment during pregnancy presents a favorable safety profile without increased rates of live birth defects,spontaneous abortion or elective termination,or fetal/neonatal toxicity.Exposure to telbivudine in the first,second and third trimester of pregnancy has been shown to significantly reduce the risk of HBV transmission from mother to child on the basis of standard immune prophylaxis procedure. AIM: To achieve an evidence-based conclusion regarding the safety and efficacy of telbivudine during pregnancy. METHODS: A pooled analysis of data from a literature search reported 1739 pregnancy outcomes (1673 live births) from 1725 non-overlapping pregnant women treated with telbivudine. The prevalence of live birth defects (3.6 / 1000) was similar to that of the nonantiviral controls (3.0 / 1000) and not increased as compared with overall prevalence (14.5 to 60/1000). No target organ toxicity was identified. Prevalence of spontaneous abortion in pregnant women treated with telbivudine (4.2 / 1000) was not increased compared with the overall prevalence (16/1000). The mother-to-child transmission rate was significantly reduced in pregnant women treated with telbivudine (0.70%) compared to those treated with the non-antiviral controls (11.9%; P <0.0001) or compared to the historical rates of hepatitis B virus (HBV) -infected population without antiviral treatment (10% -15%). RESULTS: Cumulatively 489 pregnancy cases have been reported in the telbivudine pharmacovigilance database (with a cut-off date 31 August 2014), of those, 308 had known pregnancy outcomes with 249 cases of live births (239 cases of live birth without congenital anomaly and 10 cases of live birth with In the latest antiretroviral pregnancy registry report (January January 1989 through 31 January 2015) of 27 patients exposed to telbivudine during pregnancy (18,6 and 3 during first, second and third trimester, respectively) 19 live births were reported and there were no cases of birth defects. CONCLUSION: Telbivudine treatment during pregnancy presents a favorable safety profile without increased rates of live birth defects, spontaneous abortion or elective termination, or fetal / neonatal toxicity. Expose to telbivudine in the first, second and third trimester of pregnancy has been shown to significantly reduce the risk of HBV transmission from mother to child on the basis of standard immune prophylaxis procedure.