Abstract: Objective This study aimed to compare prevention of mother-to-child hepatitis B virus (HBV) transmission by tenofovir alafenamide fumarate (TAF) and tenofovir disoproxil fumarate (TDF) in pregnant HBV carriers. Methods 62 pregnant chronic HBV carriers were encountered in our hospital between May 2022 and May 2024, and were randomly assigned to receive TDF in 31 cases or TAF anti-viral therapy in another 31 cases since gestation 26 to 28 weeks until childbirth. All newborns were inoculated with hepatitis B immune globulin and hepatitis B vaccine. Serum creatinine (sCr) level and 24-hour urinary protein quantification were measured by using a fully automated biochemical analyzer, and the estimated glomerular filtration rate (eGFR) was calculated by using the CKD-EPI formula. Serum HBeAg levels were detected by chemiluminescence, and serum HBV DNA loads were measured by fluorescent quantitative PCR system. Results By end of one year follow-up, the successful blocking of mother-to-child HBV transmission in TAT-treated women was 100.0%, not significantly different as compared to 96.8%(P>0.05) in TDF-treated women; at laboring, serum HBV DNA turned to negative in the two groups, and serum HBeAg levels dint changed greatly (P>0.05); sCr, eGFR and urine protein level in TAF-treated women were (86.1±5.9)μmol/L, (96.6±8.2)mL/(min.1.73m² and (97.5±22.1)mg/24 h, all not significantly different compared to [(88.1±5.7)μmol/L, (94.4±7.9)mL/(min.1.73m² and (99.7±28.2)mg/24 h, P>0.05) in TDF-treated women; incidences of adverse events, such as premature birth, premature rupture of membranes and gestational hypertension in the two groups were not significantly different(P>0.05). Conclusion At present, we recommend both TDF or TAF for prevention of mother-to-child HBV transmission, which warrants further clinical observation.

Key words: Hepatitis B carriers, Tenofovir alafenamide fumarate, Tenofovir disoproxil fumarate, Mother-to-child transmission, Prevention