富集孕妇外周血中胎儿细胞行胎儿性别诊断

Detection and Enrichment of Fetal Cells in Maternal Circulation for Prenatal Diagnosis of Fetal Sex

目的探讨对孕妇外周血中胎儿细胞进行非侵入性产前诊断的可行性。方法对６４例孕８～４０周孕妇外周血进行密度梯度离心法，富集胎儿细胞，并经显微镜下观察计数各种细胞所占百分比。同时，对所富集细胞经提取ＤＮＡ进行人Ｙ染色体特异ＤＮＡ扩增，判定胎儿性别并与新生儿性别进行对照。结果６４例孕妇外周血中，２５例观察到有核红细胞，占３９．０６％。６４例孕妇分娩３３例男性婴儿，其中２８例扩增出Ｙ特异带；另外３１例分娩女性婴儿，除１例出现Ｙ特异带，其余未见特异带。诊断的灵敏度为８４．８５％，特异度为９６．７７％，总符合率为９０．６３％。结论密度梯度离心法可从孕妇血中富集胎儿细胞，且所获得细胞已基本满足体外扩增Ｙ染色体基因所需要的模板量。

Objective To study fetal cells from maternal peripheral blood for prenatal diagnosis of fetal sex. Methods Samples of peripheral blood in 64 women of 8￣40 gestational weeks were collected to enrich the fetal nucleated red blood cells by density gradient centrifugation. DNA was extracted from each samples of enriched fetal cell for PCR amplification of Y chromosome specific DNA to determine fetal sex. Results Fetal nucleated red cells were found in 25 out of 64 maternal samples (39.06%). Y chromosome 149 bp was found in 28 cases of the 33 mothers given birth to male babies. One Y specific DNA sequence was detected in 31 women had female babies. The sensitivity was 84.85% and specificity 96.77%. The overall agreement of the diagnosis was 90.63%. Conclusion Density gradient centrifugation can enrich fetal nucleated red blood cells from maternal peripheral blood. Fetal sex can be determined by PCR amplification of Y chromosome specific DNA with these fetal cells.