The main objective of this study is to compare the mother-to-infant transmission rates of hepatitis B between pregnant women receiving treatment with tenofovir alafenamide and those receiving treatment with tenofovir disoproxil fumarate, after administering the hepatitis B vaccine and hepatitis B immunoglobulin to their infants at birth. Investigators define the mother-to-infant transmission rate of hepatitis B as the proportion of infants who are HBsAg positive and have serum HBV DNA \>20 IU/mL at 28 weeks of age among all live births in the experimental group.
Additionally, this study will also compare the incidence of congenital defects/malformations in infants born to mothers treated with tenofovir alafenamide and tenofovir disoproxil fumarate during the perinatal period to assess drug safety.
Pregnant women aged between 20 and 40 years old
Pregnancy duration between 20 to 28 weeks (screening for eligible patients can start from the 20th week of gestation)
Clinically diagnosed with compensated chronic hepatitis B, HBsAg positive for more than 6 months, with clinical history, signs, and test results consistent with compensated chronic hepatitis B
HBsAg and HBeAg positive in maternal serum during screening
Creatinine clearance < 100 mL/min (calculated using the Cockcroft-Gault method based on serum creatinine and ideal body weight), or hypophosphatemia (below normal range).
History of adverse renal reactions induced by Adefovir or history of Adefovir resistance.
Meeting one of the following criteria: hemoglobin < 80 g/L, neutrophil count < 1000/μL, ALT > 5 times the upper limit of normal, total bilirubin > 20 mg/L, albumin < 25 g/L, abnormal levels of creatinine or urea nitrogen.
Pregnant women with a history of miscarriage, history of giving birth to a child with congenital malformations, or history of fetal infection with hepatitis B virus.