孕早期经宫颈获取胎儿滋养细胞方法的研究

Compison of two methods for the transcervical collection of fetal cells during the first trimester of pregnancy

目的采用实时定量PCR方法对经宫颈冲洗和粘液抽吸获取的胎儿细胞进行定性定量分析,比较两种取材方法的优越性。方法分别收集孕5～9周人工流产妇女的经宫颈冲洗液和抽吸粘液各60例。提取宫颈分泌物中DNA,对Y染色体的SRY基因进行扩增和定量。对人流后的绒毛采用直接法分析染色体核型确定流产胎儿性别。结果（1）经颈管冲洗组,实时定量PCR检测出71.4%（15/21）已知男胎的SRY基因,5.13%（2/39）已知女胎的SRY基因;经宫颈粘液抽吸组,实时定量PCR检测87.5%（21/24）已知男胎的SRY基因,18.2%（6/33）已知女胎的SRY基因。两组的总性别正确预测率和男胎阳性率无统计学差异（86.7%vs 84.2%,P〉0.05;71.4%vs 87.5%,P〉0.05）。（2）实时定量PCR检测经宫颈粘液抽吸组的SRY基因拷贝数显著高于经宫颈内口冲洗组（5183.83±1976.03拷贝vs 1487.17±430.45拷贝,P〈0.05）。结论经宫颈获取的胎儿细胞可以应用于非创伤性产前诊断,经颈管抽吸粘液法能比经颈管冲洗法得到更多的胎儿细胞。

Objective： To compare the presence of fetal cells retrieving from transcervical lavage and aspiration so as to evaluate the better sampling method during frist trimester of pregnancy.Methods： 60 samples of transcervical lavage were obtained during the 5～9 weeks of pregnancy who underwent artifical abortion,and 60 samples of aspiration were obtained the same age during the 5～9 weeks of pregnancy who underwent artifical abortion too.Extraction and amplification of DNA were conducted by females to detect the presence of SRY gene of Y chromosome.The sex of fetus were determined by chromosome karyotyping of the villi.Results：（1）In transcervical lavage group,Y-derived sequences were detectived in 71.4%（15/21）samples from known male pregnancies and 5.13%（2/39） cases from known female pregnancies.In transcervical aspiration group,Y-derived sequences could be amplified in 87.5%（21/24） samples from known male pregnancies and 18.2%（6/33） cases from known female pregnancies.The overall and male correct sex prediction were achieved with no statistically significancy in two group（86.7% vs 84.2%,P〉0.05;71.4% vs 87.5%,P〉0.05）.（2）The number of copies of SRY genes of Y chromosome of the transcervical aspiration was 5183.83±1976.03 copies,significantly higher than that of the transcervical lavage group.（1487.17±430.45 copies,P〈0.05）.Conclusion： Transcervical cells sampling represents a promising prospect for non-invasive prenatal diagnosis.The present of fetal cells can be better acquired in transcervical aspiration than ranscervical lavage.