Objective: To observe the efficacy and safety related measures by blocking mother-to-child transmission of hepatitis B virus with high viral load and HBeAg positivity during pregnancy in Guizhou province. Methods: Outpatient and inpatient cases of the Department of Infectious Diseases and Obstetrics of Guizhou Medical University Affiliated Hospitals from May 2016 to July 2017 were retrospectively divided into intervention group, non-intervention group and non- hepatitis B pregnant women group; with 75 cases in each group. HBsAg and HBeAg were positive in the intervention group. Pregnant women with HBV DNA ≥10⁶ IU/ml were treated with anti-HBV therapy for 24 to 28 weeks of gestation until delivery. According to oral drugs, they were divided into tenofovir (TDF) group or telbivudine (LDT) group, non-intervention group (HBsAg and HBeAg positive), HBV DNA positive pregnant women, pregnant women with no anti-HBV drugs, non-hepatitis B pregnant women (normal pregnant women without HBV infection). Infants and young children born to the three groups of women were immunized with the national viral hepatitis B action plan. The gestational weeks and Apgar scores at birth, delivery mode, feeding mode, sex and 7-months-old age were observed and counted. Serum hepatitis B markers (HBVM) and HBV DNA were quantitatively detected. HBVM was detected by time-resolved fluorescence immunoassay (TRFIA), and HBV DNA was detected by real-time PCR (FQ-PCR). The changes of liver parameters, HBsAg, HBeAg, HBV DNA, adverse drug reactions and treatment response of pregnant intervention group before medication (12-24 weeks of gestation), 4 weeks of medication (28-32 weeks of gestation), 36-40 weeks of gestation (36-40 weeks of gestation) were statistically calculated. A t-test was used to compare the data between the measurements. Data measurements within the groups were analyzed using rank -sum test. Results: In the intervention group, therapeutic medications showed no differences in demographic and clinical characteristics between TDF group and LDT group, including liver parameters, HBsAg, HBeAg and log10HBV DNA level. Compared with pre-treatment (TDF group: 4.84 ± 2.01; LDT group: 5.08 ± 1.99), TDF and LDT were significantly lower at the end of pregnancy (TDF group: 3.06 ± 0.66; LDT group: 3.51 ± 1.20). P < 0.05); and the treatment response rate was 100%. There were no serious adverse events in the intervention group. Infants and young children (7-months-old) in the intervention group had negative HBsAg, HBeAg and HBV DNA. The mother-to-child transmission rate of HBV was zero, with blocking rate of 100%. In addition, both infants and young children had different degrees of hepatitis B protective antibodies (anti-HBs, M: 144.33), and their antibody titers were higher than that of non-intervention group (anti-HBs, M: 65.91) and non-hepatitis B pregnant women (anti-HBs, M: 58.43). The difference was statistically significant (P < 0.05), and there was no significant correlation between the use of antiviral and the way of delivery and feeding. Outcomes of mother-to-child transmission of HBV infection in infants and young children (7-months-old) delivered by three groups of pregnant women in the non-intervention groups had 20.0% (15/75)/ 17.3% (13/75) HBsAg/HBeAg positivity rate, and 17.3% (13/75) HBV DNA positivity rate. Overall, mother-to-child transmission rate of HBV infection was 20% (15/75). Furthermore, the relationship between mother's HBV DNA load and infant HBV infection in the non-intervention group showed mother's HBV DNA ≥10⁶ IU/ml. Conclusion In the non-intervention group, mother-to-child transmission of HBV occurred, and infected mothers HBV DNA was ≥106 IU/ml before delivery. This suggests that HBeAg positive and high load HBV DNA replication were independent risk factors for mother-to-child transmission of hepatitis B. Therefore, prenatal drug intervention and postpartum standard immune blockade are necessary for high-risk pregnant women with hepatitis B to achieve zero mother-to-child transmission of hepatitis B in real- clinical practice.