A cautionary note to hepatitis B e antigen (HBeAg)‐negative test results in pregnant women in an area prevalent of HBeAg‐negative chronic hepatitis B

Maternal hepatitis B e Antigen (HBeAg) positivity poses a risk for hepatitis B virus (HBV) mother‐to‐child transmission (MTCT). In resource‐constrained settings, HBeAg testing is recommended as an alternative to HBV DNA testing to establish antiviral prophylaxis eligibility. Nevertheless, the high prevalence of HBeAg‐negative chronic hepatitis B (e‐CHB) in many countries should not be overlooked. We studied HBV characteristics and explored the potential MTCT risk among HBeAg‐negative/HBsAg‐positive expectant mothers in an area prevalent of e‐CHB. Among 1348 pregnant mothers screened for HBV infection, 81 (6.0%) were HBsAg‐positive. These women were examined for HBeAg, HBV DNA, and cord blood HBV DNA. Sixteen (19.8%) of the HBsAg‐positive mothers were HBeAg‐positive, whereas 65 (80.2%) were HBeAg‐negative, including eight inactive carriers (HBsAg <100 IU/ml, HBV DNA ≤ 2000 IU/ml, and ALT < 40 IU/L). Of the remaining 57 HBeAg‐negative mothers, ten revealed HBV Basal Core Promoter or Precore mutations, with three having high viremia (HBV DNA > 200 000 IU/mL), which is associated with a high MTCT risk and therefore qualifies them for antiviral prophylaxis. This pilot study provides a cautionary note to the interpretation of negative HBeAg test results when determining eligibility for MTCT antiviral prophylaxis in situations with limited resources and in regions where e‐CHB is prevalent.