HBV Advocate Blog: Tenofovir or Telbivudine Recommended for Pregnant Women with High Viral Loads

A comprehensive overview of ways to prevent mother-to-newborn hepatitis B infection recommends the use of either tenofovir or telbivudine (Tyzeka) in pregnant women who have high levels of HBV. While treating HBV-infected pregnant women with antivirals has not yet been approved by the U.S. Food and Drug Administration, increasingly doctors are treating women with high viral loads (with HBV DNA exceeding 10 million international units per milliliter–IU/mL) in order to prevent infection of newborns.

Current medical guidelines call for screening all pregnant women for hepatitis B and immediate immunization and use of hepatitis B immune globulin (HBIG) in babies born to infected mothers.
This approach works to prevent infections in about 97% of births, but according to a recent study in the International Journal of Women's Health, about 3% of babies born to women with a 1 million IU/mL viral load will still become infected. That percentage increases to 9% among babies born to women with viral loads exceeding 100 million IU/mL.

Since 1989, antivirals have been safely used in pregnant, HIV-infected women to prevent infection of newborns, and doctors use some of those same antivirals to treat hepatitis B. So starting about five years ago, doctors began treating HBV-infected women with antivirals to tamp down their viral load before delivery.

Today, researchers recommend telbivudine and tenofovir for use in pregnant women. There is no risk of fetal toxicity with those two drugs, while animal studies have found embryo or fetal toxicity associated with lamivudine (Epivir-HBV), entecavir, and adefovir (Hepsera). Additionally, lamivudine has been found to be a weak antiviral when used during pregnancy and has caused drug resistance.

Early studies have found no transmission of HBV infection to infants when mothers are treated with either telbivudine or tenofovir.

Researchers stressed the importance of a collaborative approach by all doctors involved in a pregnant woman's care to screen for hepatitis B, immunize newborns and administer HBIG, and treat women with high viral loads with antivirals.