For mothers with chronic hepatitis B virus (HBV), there is a moderate correlation between maternal HBV DNA and cord blood HBV DNA, according to results published in Pediatrics and Neonatology.
However, the results did not indicate that cord blood HBV DNA was linked with an increased rate of vertical transmission.
The study included mother-and-child pairs in which the mother had chronic HBV infection (n=92). Mothers underwent antenatal screening for hepatitis B surface antigen, hepatitis B e antigen (HBeAg), and HIV antibodies. The researchers used real-time polymerase chain reaction to test maternal and cord blood for HBV DNA. They administered standard immunoprophylaxis with both active and passive immunization to the infants. When each infant reached 9 months of age, he or she underwent serologic testing.
The researchers found a moderate positive correlation between maternal HBV DNA and cord blood HBV DNA (r2=.521, P <.001).
The results indicated that mothers who were positive for HBeAg were more likely to be younger, to have higher HBV viral load, and to have higher cord viremia compared with mothers who were negative for HBeAg.
At 9 months of age, serologic testing showed that 1 infant was infected with HBV. This infant’s mother was positive for HBeAg; no infants of mothers who were negative for HBeAg were infected.
The researchers found that infants delivered by mothers who were HBeAg positive and those who had high HBV DNA (>6 LOG IU/mL) had an increased relative risk for cord blood viremia (1.48 and 1.62, respectively).
“This study showed that the levels of umbilical cord HBV DNA increased with maternal HBV DNA in the third trimester and correlated to the maternal HBeAg positivity,” the researchers wrote.
Lee LY, Lee GH, Mattar C, Saw S, Aw M. Maternal HBeAg positivity and viremia associated with umbilical cord blood hepatitis B viremia [published online January 5, 2019]. Pediatr Neonatol. doi:10.1016/j.pedneo.2019.01.002