Prophylactic effect of tenofovir on viral reactivation in immunocompromised pregnant women living with hepatitis B virus

The appropriate prophylaxis for hepatitis B virus reactivation (HBVr) during gestation for immunocompromised pregnant women has yet to be determined. The prophylactic efficacy and safety of tenofovir disoproxil fumarate (TDF) in hepatitis B surface antigen (HBsAg)–positive patients and the HBVr risk in hepatitis B core antibody (HBcAb)–positive patients during gestation were investigated. Eligible pregnant women were diagnosed with rheumatic diseases and were administered prednisone (≤10 mg daily) with permitted immunosuppressants at screening. HBsAg‐positive participants were instructed to take TDF; those unwilling to take TDF were followed up as the control group. Propensity score matching was applied to control for differences in confounding factors between the HBcAb‐positive and uninfected groups. Hepatopathy, maternal, pregnancy, and safety outcomes were documented as endpoints. A cohort of 1292 women was recruited from 2017 to 2020, including 58 HBsAg‐positive patients (29 in each group). A total of 120 pairs in the HBcAb‐positive and noninfection groups were analyzed. Among HBsAg‐positive patients, 6 (20.7%) cases of hepatitis flare (hazard ratio [HR]: 7.44; 95% confidence interval [CI]: 1.50–36.89; p = 0.014) and 12 (41.4%) cases of HBVr (HR: 8.71; 95% CI: 2.80–27.17; p < 0.001) occurred in the control group, while 0 occurred in the TDF prophylaxis group. The HBV level at delivery was the lowest (1.6 log(10) IU/ml) for those who received TDF during the pregestation period with a good safety profile. More adverse maternal outcomes were observed in the control group (odds ratio: 0.19, 95% CI: 0.05–0.77, p = 0.021), including one death from fulminant hepatitis and two cases of vertical transmission. No HBVr was recorded in HBcAb‐positive participants. Among immunocompromised pregnant women, prophylactic TDF during pregestation was necessary for HBsAg‐positive women, whereas regular monitoring was recommended for HBcAb‐positive women.