To investigate the efficacy of using antiviral therapy in third trimester of pregnancy to reduce mother-to-infant HBV transmission, and to access the safety of such treatment for mothers and infants.

This is a multi-centered study conducted in 12-16 collaborative hospitals in Taiwan, using tenofovir as antiviral therapy to reduce mother-to-infant transmission. The study group recruited pregnant women at 2nd to 3rd trimester receive tenofovir disoproxil fumurate (TDF) 2011-2018, June, and receive tenofovir alafenamide (TAF) 2018-2021. Control group did not receive antiviral treatment. Both group receive mother and infant follow-up up to 12 months after delivery.

Inclusion criteria:

• Women aged 20-45 years in 28 to 32 weeks of pregnancy
• Positive HBsAg and HBeAg
• Serum viral load above 6 log10 IU/mL

Exclusion criteria:

• Major systemic disease of the mother or fetus
• Positive anti-HIV or anti-HCV
• Under treatment of antiviral therapy
• Pregnant woman whose ultrasonographic examination reveals congenital anomaly of the fetus
• Pregnant woman whose amniocentesis reveals any genetic abnormality

Pregnant women