Study of Tenofovir Alafenamide Fumarate Tablets (TAF) in Blocking Mother-to-child Transmission of Hepatitis B Virus

Exclusion Criteria

• •mother with co-infection of hepatitis C virus,human immunodeficiency virus
• •evidence of decompensated liver disease
• •combined with important organ lesions which will affect patient compliance and follow-up plans, pregnant women who are expected to be difficult to complete the study
• •have a history of spontaneous abortion, or have a birth defect or congenital malformation in the last pregnancy
• •mother treated with antiviral therapy within 6 months prior to enrollment(except those treated with antiviral therapy in the last pregnancy to prevent mother-to-child transmission)
• •have a history of kidney injury, creatinine clearance \<50ml/min, urine protein positive (\>300mg/L)
• •combined with other chronic diseases and need to take immunomodulators, cytotoxic drugs or hormonal drugs during pregnancy
• •the infants' biologic father is a chronic HBV infected person
• •symptoms of threatened abortion during early pregnancy
• •evidence of hepatic cell carcinoma
• •alanine aminotransferase (ALT) \> 10 x upper limit of normal(ULN ), or total bilirubin (TBIL) \> 3 x ULN or glomerular filtration rate (GFR) \< 90 mL (min\*1.73 m2), or serum Albumin (ALB) \< 25 g/L before enrollment
• •fetal malformations detected by B-ultrasound
• •participants in other research