经母血采集胎儿细胞行产前诊断的最佳时间探讨

目的：探讨利用母血循环中胎儿细胞进行产前诊断的最佳采血时间。方法：对４１例孕龄为６～１４周的妇女连续取血，采用套式聚合酶链反应技术检测人类Ｙ染色体特异的锌指蛋白基因（ＺＦＹ）。结果：１９例妊娠男性胎儿妇女外周血ＺＦＹ随着孕龄的增加，其胎儿单拷贝基因的检出率增高，其中孕６周时检出率为１／１９（５．３％），孕１１周时为１３／１９（６８．４％），而到孕１４周时，则达到１８／１９（９５．０％）；对２２例妊娠女性胎儿妇女外周血进行ＺＦＹ检测时，无一例假阳性结果，这一检测方法在妊娠早期进行胎儿性别鉴定的总准确率达到９７．８％（４０／４１）。结论：利用母血循环中胎儿细胞进行产前诊断的最佳采血时间应在妊娠１４周，同时提示胎儿细胞最早进入母血循环中的时间在不同个体间存在明显的差异。

Optimum Time of Maternal Blood Sampling for Prenatal Diagnosis with Fetal Cells

Objective: To investigate the optimum time of maternal blood sampling for prenatal diagnosis with fetal cells. Methods: Zinc finger protein gene on Y chromosome(ZFY) sequences were examined by nested polymerase chain reaction in the peripheral blood of 41 pregnant women. Results: 19 pregnant women carrying male fetuses, and another 22 women were found to carry female fetuses. Among the 19 pregnant women, ZFY gene were detected in 1/19 (5.3%) cases before the 6th gestational weeks, in 13/19 (68.4%) before the 11th weeks, and in 18/19 (95 0%) before the 14th weeks. The results of this study clearly demonstrated that the gender prediction obviously increased along with the gestational weeks. ZFY gene was not detected in the blood of another 22 women carrying female fetuses. The final accuracy of 97.8% (40/41) was attained in all cases. Conclusion: The optimum time of maternal blood sampling is at the 14th week, and the appearance of fetal cells in maternal blood was quite case variable from the 6th to 14th weeks.