Seroprevalence and mutations in the major hydrophilic region of hepatitis B virus among pregnant women in Huzhou, China

Abstract

Background Mother-to-child transmission (MTCT) is the main cause of hepatitis B virus (HBV) infections in China. However, there is a paucity of information on seroprevalence and mutations in HBV surface genes among pregnant women in Huzhou, China. Methods In this retrospective cross-sectional study, serum markers of 31 681 pregnant women were collected and analysed. The surface genes were amplified and directly sequenced. Mutations in the major hydrophilic region (MHR) were analysed in 171 randomly selected subjects. Results The seroprevalence of HBV infection was 3.32% (1053/31 681). The predominant HBV genotypes were B (57.4%) and C (42.6%). Pregnant women ≥30 y of age exhibited a higher hepatitis B surface antigen–positive rate than those <30 y of age. MHR mutations were found in 42.6% (72/169) of the subjects, several of which were escape mutations. The mutational frequencies in the a-determinant and first loop (AA124-137) were higher in genotype C than genotype B. Pregnant women with MHR mutations showed increased alanine transaminase, aspartate transaminase and gamma-glutamyl transpeptidase levels and decreased HBV loads. Conclusions The HBV seroprevalence among pregnant women in Huzhou was intermediate. MHR mutations occur and the risk of MTCT still persists. Therefore, early screening, intervention and care for HBV-infected pregnant women should be strengthened to minimize or prevent MTCT of HBV.