Placental infection of hepatitis B virus among Thai pregnant women: Clinical risk factors and its association with fetal infection

Abstract

Objectives To identify the risk factors of placental and fetal infections among HBsAg‐positive women. Methods A prospective cohort study involving HBsAg‐positive pregnant women was conducted. Maternal risk factors, including serum HBeAg status, anti‐HBcIgM, and HBV‐DNA levels, were determined. Placental infection was identified by PCR and confirmed by DNA sequencing. Fetal infection was defined as a positive umbilical cord blood HBV‐DNA at birth. Results A total of 96 HBsAg‐positive women were enrolled in the study. The prevalence of placental infection was high (44 of 96; 45.8%) among HBsAg‐positive women. The major risk factors for placental infection were high maternal viral load and the presence of HBeAg. Fetal infection was detected in one quarter of HBsAg‐positive women (25 of 95; 25.3%). The risk of fetal infection was strongly associated with placental infection (78.3%), high maternal viral load, and the presence of HBeAg. There was no significant difference in perinatal outcomes between the groups with and without placental infection. Data on rates of chronic HBV infection in infants after fetal infection were not available. Conclusion A significant association between maternal measures of viral replication and placental and fetal infection was demonstrated. These findings suggest that transplacental infection prior to birth may be a mechanism contributing to the higher rates of newborn prophylaxis failure in women with a high viral load.

Comment on “Placental infection of hepatitis B virus among Thai pregnant women: Clinical risk factors and its association with fetal infection”

“…The virions in newborn infants at this moment were derived from their mothers during birth process because of the transfer of maternal blood into fetuses that resulted from repetitive and strong uterine contractions. Although Sirilert et al mentioned that the fetal HBV infection is not equivalent to mother‐to‐child‐transmission, the discussion contents of the fetal HBV infection in their article are actually same as the mother‐to‐child transmission 1 . Moreover, the term fetal HBV infection has the fixed interpretation, referring to intrauterine HBV infection.…”

“…transmission, the discussion contents of the fetal HBV infection in their article are actually same as the mother-to-child transmission. 1 Moreover, the term fetal HBV infection has the fixed interpretation, referring to intrauterine HBV infection. Arbitrarily changing the definition is confusing.…”

“…Perinatal HBV infection even in infants of HBsAg-positive mothers who had amniocentesis during pregnancy was just 2.8% after immunoprophylaxis, 9 much lower than the reported 25.3% fetal infection. 1…”

“…We are concerned about the conclusion of an article authored by Dr. Sirilert and colleagues that the fetal infection of hepatitis B virus (HBV) occurred in 25.3% of newborn infants of mothers with positive hepatitis B surface antigen (HBsAg) based on positive HBV DNA in umbilical cord blood at birth 1 . We considered the statement that “fetal infection was defined as a positive test for HBV DNA, HBeAg and anti‐HBc IgM in cord blood” in the Methodology is incorrect, leading to the erroneous interpretation of their results.…”

“…Sirilert et al did not present the results of IgM antibodies against hepatitis B core antigen (anti‐HBc IgM), although they mentioned that anti‐HBc IgM is a marker of fetal infection 1 . Indeed, anti‐HBc IgM positive in cord blood can define fetal HBV infection, but other studies showed that anti‐HBc IgM is totally absent in cord blood 3,8 …”