A randomized clinical trial conducted across seven tertiary care hospitals in China evaluated whether tenofovir disoproxil fumarate initiated at gestational week 16 with infant hepatitis B vaccination was as effective as the standard approach of initiating tenofovir disoproxil fumarate at week 28 with both hepatitis B vaccination and hepatitis B immune globulin for preventing mother-to-child transmission of hepatitis B virus.

In the study, published in JAMA Network, researchers enrolled 280 pregnant women with hepatitis B virus (HBV) DNA levels exceeding 200,000 IU/mL between June 2018 and February 2021. In the intention-to-treat analysis, the mother-to-child transmission (MTCT) rate was 0.76% (n = 1/131) in the experimental group compared with 0% (n = 0/142) in the standard care group, with a between-group difference of 0.76% (upper 90% confidence interval [CI] = 1.74%), meeting the noninferiority margin of 3%.

In the per-protocol analysis, both groups recorded a 0% MTCT rate, confirming the findings. Secondary outcomes included significantly higher maternal virological suppression in the experimental group at delivery (HBV DNA < 200,000 IU/mL: 99.2% vs 94.2%, P = .02). Rates of congenital defects were lower in the experimental group (2.3% vs 6.3%, P > .05).

Tenofovir disoproxil fumarate (TDF) therapy was generally well tolerated with no significant safety concerns. The findings suggested that initiating TDF earlier during pregnancy combined with HBV vaccination could offer an alternative where hepatitis B immune globulin (HBIG) is unavailable.

Conflict of interest disclosures can be found in the study.