Incidence of mother to child transmission of hepatitis B virus and its influencing factors in Pudong New Area of Shanghai

Objective To study the transmission of hepatitis B virus(HBV)from mother to child and the related influencing factors,so as to provide evidence for HBV control.Methods An epidemiological survey was conducted on 445mother-infant pair participants with positive maternal HBsAg from 4hospitals in Pudong New area of Shanghai.Peripheral blood samples of mothers and the umbilical cord blood samples of the infants were collected to detect the markers and DNA titer of HBV.HBsAg positive and HBV DNA positive in umbilical cord blood were defined as HBV positive in the infants.All the newborns received vaccination after birth according to the national regulation.Of the 445participants,104newborns were followed for 7months after birth,and the blood samples were collected and the markers and DNA titer of HBV were examined.HBsAg positive after 7months was defined as immune failure.Results The positive rate of HBV in the newborns was 8.0%for mothers with positive HBsAg in our study.The HBV positive rate of newborns whose mothers were positive for both HBsAg and HBeAg was significantly higher than whose mothers were only HBsAg positive(26.7%vs 1.8%,P0.05).The HBV positive rate was significantly higher in newborns whose mothers with HBV DNA 106 copies/mL compared with those with HBV DNA 106 copies/mL(23.6%vs 2.3%,P0.05).The immune failure rate of hepatitis B vaccine was 3.8% 7months after birth in our study,with all their mothers being positive for both HBsAg and HBeAg.Conclusion The maternal HBeAg positivity and the high concentration of HBV DNA are the main risk factors of neonatal infection,and they may lead tonon-response to hepatitis B vaccine.