This study evaluates generic emtricitabine(FTC) efficacy and safety in Chinese naive pregnant HBsAg positive patients in prevention of HBV vertical transmission. Single group patients were enrolled to receive emtricitabine till 24 weeks after delivery.

Single group patients were enrolled to receive emtricitabine till 24 weeks after delivery, which include HBeAg positive patients. Patients and their newborns were followed till 48 weeks after delivery to evaluate the efficacy of prevention of vertical transmission.

Inclusion Criteria:

• HBsAg positive for more than 6 months
• HBeAg positive patients: HBV DNA ≥ 5log10 copies/ml
• HBeAg postive patients: ALT≥2×ULN;or liver biopsy G≥2;or liver biopsy S ≥2;or liver biopsy Knodell HAI ≥ 4
• HBeAg negative patients: HBV DNA ≥ 4log10 copies/ml
• HBeAg postive patients: ALT≥2×ULN;or liver biopsy G≥2;or liver biopsy S ≥2;or liver biopsy Knodell HAI ≥ 4
• Nucleoside/nucleotide naive paitents
• Diagnosed as ≥ 28 weeks pregnancy

Exclusion Criteria:

• Diagnosed HCC with AFP and ultrasound, CT or MRI
• Creatine >130μmol/L or Ccr < 70mL/min
• Hemoglobin <100g/L
• Coinfected with HAV,HEV,HCV,HDV or HIV
• ANA > 1:100
• Uncontrolled cardiovascluar diseases, kidney diseases,lung diseases, neurological diseases, digestive diseases,metabolic disorders, immune-compromised diseases or cancer
• Drug abuse or alcohal addiction
• Previous history of taking agents of lamivudine, adefovir, tenofovir entecavir or telbivudine
• Long-term use of immunosuppressor or immunomodulator 6 months before enrollment to this trial
• Underwent liver transplantation or liver transplantation in schedule
• Allergic to nucleoside or nucleotide analogues
• family history of genetic defects disease
• Abnormal results in fatal defects screening
• HBsAg positive sperm provider pregnancy