Tenofovir Disoproxil Fumarate as an Adjunctive Therapy for the Prevention of Vertical Transmission of Hepatitis B Virus Infection

Background: Despite the use of HBIG and HBV immunization, HBV perinatal transmission  occurs in 10–30% of infants born to highly viremic mothers. We evaluated the efficacy and safety of Tenofovir Disoproxil Fumarate (TDF) use during the last trimester of pregnancy as adjunctive therapy to hepatitis B immunization in reducing HBV transmission in highly viremic HBeAg+ mothers.

Method: Between 6/2010 and 6/2013 we evaluated prospectively fourteen pregnant women with chronic hepatitis B infection referred to our clinic who were  HBeAg+ with HBV DNA levels >1.0 x10⁷copies/ml  and received TDF 300 mg/ day from week 28 until delivery. All of the patients included in the study had previously given birth to at least one child infected with hepatitis B despite the immunization with HBIG and HBV vaccine. All infants received HBIG within 12 hours postpartum and recombinant HBV vaccine at 0,1 and 6 months. HBsAg and Anti-HBs results of infants at week 28-32 were used to determine perinatal transmission rate.    

Result: TDF treatment was associated with a marked reduction in serum HBV DNA  before delivery compared with baseline (mean 4.89 ± 1.65 vs  9.12 ± 0.75 log₁₀copies/ml, respectively; p<0.01). All fourteen infants were born without complication and birth defects. All infants were breastfed, had HBsAg negative and Anti-HBs positive results at week 28-32 after birth. 

Conclusion: Our results suggest that TDF used during the thırd trimester of pregnancy in HBeAg+ highly viremic mothers with simultaneous administration of HBIG and HBV vaccine to the newborns  can safely prevent  perinatal HBV transmission. Prospective and larger studies are needed to confirm these findings.