# 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

## TL;DR

This study compares two drugs, TAF and TDF, for preventing hepatitis B transmission from mothers to their babies, finding both effective but TAF safer for the kidneys.

## Contribution

The study provides a direct comparison of TAF and TDF for HBV prevention in treatment-naïve mothers, highlighting TAF's superior renal safety.

## Key findings

- TAF and TDF similarly reduced HBV DNA levels and MTCT rates (1.08% vs. 0.95%).
- TAF showed no significant renal effects, while TDF caused increased serum creatinine and decreased eGFR.
- No congenital malformations or developmental abnormalities were observed in newborns from either group.

## Abstract

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.

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.

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.

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.