RESUMEN
Hepatitis B virus (HBV) vertical transmission remains a worldwide issue but is fairly uncommon in the western world due to routine screening and vaccination. Universal screening of pregnant women during the second trimester facilitates interruption of mother-to-child transmission (MTCT) by identifying HBV-infected mothers for whom intervention may reduce MTCT risk. HBV DNA level is the single most important predictor of MTCT. Other risk factors include HBeAg, HBe Ab, anti-HB core IgG, and HIV status. Current recommendations for infants born to HBsAg-positive mothers include administration of HBIG within 12 hours of birth and first dose of HBV vaccine within 24 hours of birth. Antiviral therapy is recommended in the third trimester of pregnancy in a subset of patients based on HBeAg and HBV DNA status for prophylaxis of MTCT, although discontinuation of antivirals after delivery is associated with significant increased risk of flares. This article outlines the data for prevention of vertical transmission of HBV.