The use of tenofovir disoproxil fumarate (TDF) during pregnancy resulted in lower rate of mother-to-child transmission of hepatitis B virus (HBV) compared with those who received usual care without antiviral therapy, a recent study finds.
To assess the efficacy of TDF use during pregnancy for the prevention of HBV transmission from mother to child, researchers randomized 197 mothers who were positive for hepatitis B e antigen (HBeAg) and who had an HBV DNA level higher than 200,000 IU per millilitre to receive usual care without antiviral therapy (n=100) or TDF (n=97; 300 mg/day) from 30 to 32 weeks of gestation until postpartum week 4. The participants were followed until postpartum week 28. All the infants received immunoprophylaxis.
The primary outcomes were the rates of mother-to-child transmission and birth defects. The secondary outcomes were the safety of TDF, the percentage of mothers with an HBV DNA level of less than 200,000 IU per milliliter at delivery, and loss or seroconversion of HBeAg or hepatitis B surface antigen at postpartum week 28.
At delivery, 68 percent of the mothers in the TDF group, as compared with 2 percent in the control group (2 of 100), had an HBV DNA level of less than 200,000 IU per milliliter (p<0.001). At postpartum week 28, the rate of mother-to-child transmission was significantly lower in the TDF group than in the control group, both in the intention-to-treat analysis (5 vs 18 percent; p=0.007) and the per-protocol analysis (0 vs 7 percent; p=0.01).
The maternal and infant safety profiles were similar in the TDF group and the control group, including birth-defect rates (2 and 1 percent, respectively; p=1), although more mothers in the TDF group had an increase in the creatine kinase level. After the discontinuation of TDF, alanine aminotransferase elevations above the normal range occurred more frequently in mothers in the TDF group than in those in the control group (45 vs 30 percent; p=0.03). The maternal HBV serologic outcomes did not differ significantly between the groups.