# Postpartum TDF continuation in high HBV-DNA mothers: safety for breastfeeding and enhanced infant immunity

## TL;DR

Continuing TDF after childbirth and breastfeeding is safe and helps reduce HBV transmission and improve infant immunity in mothers with high HBV-DNA.

## Contribution

Demonstrates the safety and efficacy of postpartum TDF continuation during breastfeeding for high HBV-DNA mothers.

## Key findings

- TDF-BF Group had significantly lower HBV transmission and HBsAg positivity in infants.
- Infants in the TDF-BF Group showed higher protective anti-HBs levels at 12 months.
- TDF was not detected in infant plasma, supporting its safety during breastfeeding.

## Abstract

High HBV-DNA load in pregnant women increases the risk of vertical transmission to infants. Tenofovir disoproxil fumarate (TDF) is an effective antiviral treatment, but its safety and efficacy in breastfeeding mothers with high HBV-DNA loads remain unclear.

This retrospective cohort study included 210 high HBV-DNA load mothers, divided into a TDF-BF Group (n = 110) that continued TDF postpartum and breastfed, and a Non-TDF-BF Group (n = 100) that discontinued TDF postpartum but breastfed. Primary outcomes were HBV transmission, infant HBV serostatus, neonatal safety outcomes, and maternal outcomes.

The TDF-BF Group had significantly lower rates of vertical HBV transmission (P < 0.05) and HBsAg positivity at 12 months (P < 0.05) compared to the Non-TDF-BF Group. A higher proportion of infants in the TDF-BF Group had protective levels of anti-HBs at 12 months (P = 0.046, indicating borderline significance). Infant safety outcomes related to growth were comparable between groups, but the TDF-BF Group had significantly higher serum creatinine levels and lower serum phosphate levels (all P < 0.05, raising a potential signal for renal function differences). Maternal outcomes favored the TDF-BF Group, with better HBV-DNA suppression and ALT normalization.

Postpartum continuation of TDF and breastfeeding is an effective and safe strategy for reducing vertical HBV transmission and promoting infant immunity in high HBV-DNA load mothers. Notably, Tenofovir was not detected in the infant plasma, supporting the safety of this approach.