Lamivudine versus tenofovir for preventing mother-to-child transmission of hepatitis B virus in highly viremic pregnant women: A prospective, matched cohort study

Objective: To evaluate the efficacy and safety of lamivudine and tenofovir in preventing mother-to-child transmission of hepatitis B virus (HBV) in pregnant women with chronic HBsAg positivity and high viral load. Methods: A prospective, matched cohort study was conducted on pregnant women with high viral load (>10 6 copies/mL) from March 2015 to March 2018 at two hospitals in Vietnam. Infants born to these women were followed up until January 2019. Data were collected on maternal HBV DNA load, organ function test results, and adverse reactions, as well as infant HBV markers at birth and at 1, 6, and 12 months of age. Data were analyzed between February and June 2019. Results: A total of 80 pregnant women were enrolled and divided into lamivudine group ( n =39) and tenofovir group ( n =41). In the tenofovir group, the median maternal HBV DNA load decreased sharply from 7.2 (6.8-7.6) log 10 copies/mL before treatment to 4.4 (2.8-5.6) log 10 copies/ mL at delivery, which was a significantly greater reduction than that observed in the lamivudine group. The mean ALT and creatinine levels in both groups increased by no more than 2-fold compared with baseline, but remained within the normal range. The efficacy of preventing HBV mother-to-child transmission was similar between the two infant groups: 4.8% in the lamivudine group and 3.8% in the tenofovir group. Conclusions: Tenofovir should be the preferred option for preventing mother-to-child transmission of hepatitis B virus in pregnant women with high HBV viral load. Future studies with larger sample sizes and additional control groups are warranted to strengthen the evidence and improve the quality of treatment recommendations.