A Review of Antiviral Use for the Treatment of Chronic Hepatitis B Virus Infection in Pregnant Women.

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) remains high even with the proper use of active-passive immunoprophylaxis in newborns. Mothers with significant viremia are at a much higher risk of MTCT; therefore, treatments aimed at lowering HBV DNA levels during pregnancy may ultimately decrease global disease burden. The exact threshold for treatment remains controversial; however, most studies have accepted levels greater than 2 × 5 log10 IU/mL as significant viremia. We reviewed the most recent literature on antiviral efficacy, maternal and fetal safety, and viral resistance patterns when used for short-duration therapy in pregnancy. The literature review shows that antiviral therapy during pregnancy significantly reduces maternal HBV DNA levels with subsequent reductions in infant HBV infections. Tenofovir disoproxil fumarate (TDF) is associated with mild gastrointestinal distress and may cause decreased fetal bone growth (although long-term studies are needed to evaluate the clinical significance of this finding), and the impact of this drug is likely limited when use is restricted to the third trimester. Lamivudine and telbivudine remain inferior to TDF in regard to resistance profiles. Overall, TDF, lamivudine, and telbivudine in conjunction with standard immunoprophylaxis are recommended for use in pregnant women with significant HBV viremia (>2 × 5 log10 IU/mL) to prevent MTCT and appear reassuring in regard to their maternal and fetal safety profiles.