OBJECTIVETo evaluate the efficacy and safety of telbivudine use during the second and third trimester of pregnancy for reducing hepatitis B virus (HBV) transmission from highly viremic hepatitis B e antigen-positive (HBeAg+) mothers to their fetuses.

METHODSPregnant women, between weeks 20 to 32 of gestation, who were HBeAg+ and had HBV DNA more than 1.0*10(7) copies/mL were enrolled in our study. The women were offered inclusion into one of two treatment arms, based upon their personal preference: telbivudine or no telbivudine. The patients in the telbivudine treatment arm were administered 600 mg/d telbivudine at least until postpartum week 4. All delivered infants in both treatment arms were administered hepatitis B immune globulin (HBIG; 200 IU) within 12 hours of delivery and recombinant HBV vaccine (20 mug) at 0, 1 and 6 months. The HBV perinatal transmission rate was determined by measuring HBsAg and HBV DNA in infants at postpartum week 28.

RESULTSA total of 220 pregnant women were enrolled in our study, 120 chose the telbivudine arm and 100 chose the control arm. All telbivudine treated subjects were registered in the Antiretroviral Pregnancy Registry. Telbivudine treatment was associated with a marked reduction in the mothers' serum HBV DNA, HBeAg and ALT levels before delivery. A striking decline of HBV DNA levels in treated mothers was observed at week 2 of treatment, which was followed by a gradual and steady decrease that continued until delivery. Thirty-seven (31%) of the telbivudine-treated mothers and none (0%) of the untreated controls had polymerase chain reaction-undetectable viremia at delivery. At week 28, 0% of the infants delivered from telbivudine-treated mothers were HBsAg+ or HBV DNA+, as compared to 8% HBsAg+ or HBV DNA+ in the untreated control arm (P = 0.002). No telbivudine discontinuations occurred from adverse events, and no congenital deformities were observed in the infants delivered to telbivudine-treated mothers. Eighty mothers discontinued telbivudine at week 4 postpartum, and there were no cases of severe hepatitis. There were no significant differences between the two treatment arms for postpartum hemorrhage, adverse events during pregnancy, cesarean section, gestational age, or infants' height/weight or Apgar scores.

CONCLUSIONSTelbivudine use during the second and third trimester of pregnancy in HBeAg+ highly viremic mothers can safely reduce perinatal HBV transmission rates. Telbivudine was well-tolerated by our patient group. Furthermore, no safety concerns were observed in either the telbivudine-treated mothers or their delivered infants in short term follow-up.