Decreased neonatal hepatitis B virus (HBV) viremia by maternal tenofovir treatment predicts reduced chronic HBV infection in children born to highly viremic mothers.

Background: Maternal anti-viral treatment prevents mother-to-infant transmission of hepatitis B virus (HBV), but the role of neonatal viremia on subsequent HBV infection is not clear.

Aims: To investigate the effect of maternal anti-viral treatment on neonatal serum HBV DNA and hepatitis B surface antigen (HBsAg) in infants born to highly viremic mothers and the roles of neonatal markers in predicting chronic HBV infection in children.

Methods: Serum HBV DNA and HBsAg were tested in children. Of the 201 pregnant mothers, 110 received tenofovir during the third trimester. Chronic infection in children was defined by HBsAg seropositivity at 6 or 12 months lasting more than 6 months.

Results: The maternal HBV viral loads from baseline to delivery were 8.25 ± 0.48 to 4.29 ± 0.98 log  IU/mL; and 8.29 ± 0.49 to 8.12 ± 0.68 log  IU/mL in the tenofovir and control group respectively. Of the 208 children, those in the tenofovir group had a lower rate of neonatal HBV DNA seropositivity at birth (5.22% vs 30.11%, P < 0.0001) and HBsAg seropositivity at 6 months (1.74% vs 11.83%, P = 0.003) and 12 months (1.74% vs 10.75%, P = 0.007). In a first multivariate analysis, maternal HBV DNA level at delivery (odds ratio = 1.70, P = 0.0172) and neonatal HBsAg positivity (odds ratio = 19.37, P < 0.0001) were significantly associated with children's chronic HBV infection. In a second model, neonatal HBV DNA positivity was a strong independent influence variable (odds ratio = 61.89, P = 0.0002).

Conclusions: Maternal tenofovir therapy decreased maternal viral load and neonatal viremia. Positive neonatal HBV DNA was highly correlated with chronic HBV infection in children. Clinical Trial Identifier: NCT01312012.