Relationship between HBV viremia level of pregnant women and intrauterine infection:neated PCR for detection of HBV DNA

AIM:To determine the incidence of hepatitis B virus (HBV) in trauterine infection and to explore the relationship between HBV viremia level of pregnant women and HBV intrauterine infection.METHODS: Sixty-nine pregnant women were divided into three groups. Group A, 41 HBsAg positive patients, 14 of them were HBeAg positive (group A1), and 27 HBeAg negative (group A2); Group B, 12 HBsAg negative patients, but positive for anti-HBs and/or anti-HBe and/or anti-HBc; and Group C, 16 patients negative for all HBV markers. Blood samples of mothers were taken at delivery, samples of their infants were collected within 24 hours after birth (before injection of HBIG and HBV vaccine). All the serum samples were stored at -20°. HBV serum markers were tested by radioimmunoassay and HBV NDA were detected by nested polymerase chain reaction.RESULTS: In group C, all of 16 newborns were negative for HBsAg and HBV DNA. In group A, 7 infants were HBsAg positive (17.1%), and 17 (41.5%) were HBV DNA positive (P < 0.05). The incidence of intrauterine HBV infection was much higher in group A1 than that in group A2 (HBsAg 42.9% vs 3.7%, HBV DNA 92.9% vs 14.8%, P < 0.05). The incidence of HBV intrauterine infection was significantly different between high and low HBV viremia of mothers (93.3% vs 42.9%,P < 0.05).CONCLUSION: The incidence of HBV intrauterine infection is high when HBV DNA in newborns detected with nested PCR is used as a marker of HBV infection. It is related to HBV viremia level of mothers.