Efficacy and Safety of Tenofovir Alafenamide Fumarate and Tenofovir Disoproxil Fumarate for Preventing Mother-to-Child Transmission of Hepatitis B in Treatment-Naïve mothers: An Observational Study

Background Mother-to-child transmission (MTCT) is the primary cause of hepatitis B virus (HBV) infection. Antiviral therapy is crucial to reduce MTCT for pregnant women with high viremia. Tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) are the first-line antiviral drugs for hepatitis B. This study aimed to evaluate the effectiveness and safety of TAF and TDF in preventing HBV MTCT among treatment-naïve mothers. Methods A total of 290 pregnant women with HBsAg positive for > 6 months, and HBV DNA ≥ 2 × 10^5 IU/ml or HBeAg positive were enrolled. Mothers received either TDF or TAF therapy and newborns received hepatitis B immunoglobulin and recombinant yeast hepatitis B vaccine. MTCT was evaluated during a one-year follow-up period after birth. Results 290 pregnant women (185 with TDF therapy and 105 with TAF therapy) and 296 newborns (190 in TDF group and 106 in TAF group) were included. Both TDF and TAF effectively deceased HBV DNA levels with no significant difference, and the MTCT rates in TDF group and TAF group were similarly low (1.08% vs. 0.95%, P > 0.05). Moreover, no congenital malformations or growth and developmental abnormalities in newborns were observed in either group. However, serum creatinine was significantly higher and eGFR decreased significantly when treated by TDF, whereas TAF showed no significant renal effects. Conclusions Both TAF and TDF are effective in preventing HBV MTCT, with comparable MTCT rates. However, TAF demonstrated superior renal safety, making it a preferable option for preventing HBV MTCT in treatment-naïve mothers.