Researchers observed a significant association between the presence of higher hepatitis B DNA at 28 to 30 weeks of gestation in pregnant women and immunoprophylaxis failure in newborns.
“The risk of vertical transmission leading to chronic infection is dramatically reduced by administering hepatitis B immunoglobulin (HBIG) to newborns at birth together with a complete course of HBV vaccination,” the researchers wrote. “A high maternal HBV DNA level during pregnancy is the strongest risk factor leading to immunoprophylaxis failure.”
Between January 2014 and December 2016, the researchers observed 641 women in Hong Kong who gave birth to 654 infants (13 pairs of twins), including 155 women who were HBeAg-positive.
In the prospective study, all newborns received 10 g HBV vaccines and 110 IU HBV immunoglobulin intramuscularly within 12 hours of birth and received HBV vaccines of the same dosage at 1 month and 6 months. The researchers analyzed the infants’ HBsAg levels at 9 months to 12 months.
Seven infants born to the women with HBV had immunoprophylaxis failure. The mothers of these children had HBV DNA over 8 log10 copies/mL. While infants born to mothers with HBV DNA below or at 8 log10 had no risk for immunoprophylaxis failure, the risk for immunoprophylaxis failure in those born to mothers with HBV DNA between 8 log10 and 8.99 log10 was 8.6% and 3.1% for those with HBV DNA above 9 log10.
Compared with infants who had no risk for immunoprophylaxis failure, 5.79% (95% CI, 2.36-11.56) of infants born to women with HBV DNA at or over 8 log10 and 4.52% (95% CI, 1.83-9.08) of infants born to women with HBeAg-positive status had immunoprophylaxis failure.
By Talitha Bennett