Babies born to mothers with chronic hepatitis B virus (HBV) and high HBV DNA levels remain at risk for HBV transmission and development of chronic infection despite routine immunoprophylaxis at the time of birth. Treatment of pregnant women with an oral antiviral agent (lamivudine, telbivudine, or tenofovir) during the third trimester was recommended to reduce maternal HBV DNA levels, although high-quality studies were lacking to establish the efficacy of this approach to reduce mother-to-child transmission. During the past year, Pan and colleagues published results from a randomized controlled trial providing compelling evidence that treatment of mothers with HBV DNA levels >200,000 IU/mL with tenofovir during the third trimester reduces the risk of mother-to-child HBV transmission.1
In this study, 200 HBeAg-positive mothers with HBV DNA levels >200,000 IU/mL were randomized to tenofovir 300 mg daily from 30 to 32 weeks’ gestation until week 4 postpartum, or to a control group whom received no antiviral therapy. All babies received hepatitis B immune globulin and vaccination at time of birth. Mothers did not breastfeed on tenofovir. HBV transmission was assessed at week 28 postpartum.
- In intention-to-treat analysis, in which patients who were lost to follow-up or discontinued treatment were considered as treatment failures, the HBV transmission rate was 5% (5/97) in the tenofovir group compared with 18% (18/100) in controls.