中文摘要：

目的探讨慢性HBV感染母亲血清HBVDNA载量及新生儿外周血中游离母亲DNA与新生儿HBV感染的关系。方法等位基因特异性PCR及半套式PCR技术检测慢性HBV感染母亲及其新生儿外周血中游离母亲DNA。荧光定量PCR对母亲外周血血清中HBVDNA定量检测。数据采用阳性率、x2检验、Fisher精确概率等进行统计学分析。结果筛选出36对母儿信息病例对，有26个新生儿外周血中检测到游离母亲DNA，占72．2％。母一胎DNA转移与新生儿HBsAg、HBVDNA阳性均无关（Fisher精确概率分别为0．278、1．000，均P〉0．05），而与新生儿外周血单个核细胞（PBMC）HBV感染有关（Fisher精确概率-0．026，P〈0．05）。母-胎DNA转移与母亲血清HBVDNA载量无关（x2=2．097，P〉0．05），随着母亲血清HBVDNA载量的增加，其发生新生儿血清HBVDNA阳性的危险性呈增高趋势（总X2=62．21，P〈0．05；趋势x2=58．46，P〈0．05），而母亲血清HBVDNA载量与新生儿PBMCHBVDNA阳性无关（总x2=4．82，P〉0．05）。结论母胎DNA转移与新生儿PBMCHBV感染有关，可能是新生儿HBV感染的一个因素。随着母亲HBVDNA载量增高，新生儿血清HBVDNA阳性的危险性越高。

英文摘要：

Objective To study the relationships between serum hepatitis B virus （HBV） DNA level in chronic HBV infected mothers, free maternal DNA in newborns＇ peripheral blood and HBV infection of newborns. Methods Free maternal DNA in newborns＇ peripheral blood was amplified by allele-specific polymerase chain reaction （As-PCR） and heminested polymerase chain reaction （heminPCR）. Serum HBV DNA of pregnant women were detected by fluorescence quantitative real-time PCR. The relationships between mothers＇ serum HBV DNA level, mother-to-fetus DNA transfer and newborns HBV infection were analyzed by SPSS 13.0 software. Results Thirty-six pairs of motherfetus informative cases were selected and free maternal DNA in the peripheral blood was detected in 26 newborns （72.2%）. Statistical analysis indicated that mother-to-fetus DNA transfer was not related with HBsAg, HBV DNA positive in newborns （Fisher exact probabilities were 0. 278 and 1. 000, respectively; both P〉0. 05）, while it was related with HBV infection in the peripheral blood mononuclear cell （PBMC） of newborns （Fisher exact probability was 0. 026, P〈 0. 05）. Free maternal DNA transfer was not related with mother HBV DNA level （x2 =2. 097, P〉0.05）. The risk of HBV DNA positive in newborns increased with mother serum HBV DNA increasing （ total x2 =62.21, P〈0. 05; tendency x2= 58. 46, P〈0.05）. There was no relationship between mother serum HBV DNA level and PBMC HBV DNA positive in newborns （total x2 =4. 82, P〉0. 05）.Conclusions DNA transfer from HBV infected mother to fetus is related with PBMC HBV infection in newborns, which could be a risk factor of HBV infection in newborns. The risk of serum HBV DNA positive in newborns increases with mother serum HBV DNA level increasing.