Effect of antiviral therapy in reducing perinatal transmission of hepatitis B virus and maternal outcomes after discontinuing them

Abstract

Background/aims: There have been numerous efforts to reduce mother-to-child transmission (MTCT) of hepatitis B virus (HBV) with antiviral agents during pregnancy. However, there are limited data regarding the outcomes of pregnant women after delivery. This study was performed to evaluate the efficacy of antiviral agents in preventing MTCT of HBV and maternal long-term outcomes.

Methods: The HBV-infected pregnant women treated with antiviral agents to prevent MTCT were retrospectively reviewed. Forty-one pregnant women who received telbivudine or tenofovir during late pregnancy (28-34 week) were analyzed. Hepatitis B virus surface antibody (HBsAb) positivity was tested in 43 infants after 7 months of birth. Eleven mothers were followed >1 year after delivery.

Results: The mean HBV DNA titer before antiviral therapy was 8.67 (6.60-9.49) log copies/mL, and the median age at delivery was 32 years (range, 22-40). Eleven patients were treated with tenofovir and 30 with telbivudine. The median duration was 57 days (range, 23-100), and the median HBV DNA titer at birth was 5.06 log copies/mL (range, 2.06-6.50). Antiviral treatments were associated with significant HBV DNA reduction (P<0.001). Among 43 infants (two cases of twins), HBsAb was not detected in two, subsequently confirmed to have HBV infection. Biochemical flare was observed in two of 11 mothers followed >12 months, and an antiviral agent was administered.

Conclusion: Antiviral treatment during late pregnancy effectively reduced MTCT. Long-term follow-up should be required in such cases. In addition, given that maternal biochemical flare occurred in 18% of mothers, re-administration of antiviral agents might be required.

Keywords: Antiviral agents; Hepatitis B virus; Mother-to-child transmission; Postpartum; Pregnancy.

Figure 1.

Flow chart of patients. Forty-one pregnant women with chronic hepatitis B virus were analyzed. Thirty pregnant women received telbivudine, and eleven received tenofovir during late pregnancy. HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; LdT, telbivudine; TDF, tenofovir.

Figure 2.

Virologic efficacy of antepartum antiviral therapy. (A) In the telbivudine-treated group, the median baseline HBV DNA loads were 8.64 (7.00–9.30) log copies/mL, falling to 5.08 (2.06–6.39) log copies/mL at delivery, a mean reduction of 3.65 log copies/mL (P<0.001). (B) In patients treated with tenofovir, the median baseline HBV DNA was 8.7 (6.60–9.49) log copies/mL, which decreased to 4.88 (2.5-6.5) log copies/mL at delivery, with a mean reduction of 3.8 log copies/mL (P<0.001). HBV, hepatitis B virus; LdT, telbivudine; TDF, tenofovir.

Figure 3.

Maternal virologic and biochemical changes after withdrawal. (A) One mother was 33 years old, HBeAg-positive, and nulliparous. On day 229 postpartum, she began treatment with entecavir due to biochemical flare. (B) The other mother was 34 years old, HBeAg-positive, and nulliparous. On postpartum day 256, tenofovir was initiated due to biochemical flare. (C) A mother who was 29 years old, HBeAg-positive, nulliparous, and used telbivudine in late pregnancy experienced a temporary elevation in ALT level and showed spontaneously decreasing HBV DNA level. (D) A 32-year-old mother who was HBeAg-negative, nulliparous, and used tenofovir used in late pregnancy experienced a temporary elevation in both HBV DNA and ALT levels after delivery and exhibited a spontaneous decrease in HBV DNA level. HBeAg, hepatitis B e antigen; ALT, alanine aminotransferase; HBV, hepatitis B virus; ETV, entecavir; TDF, tenofovir.