目的 研究荧光原位杂交技术在快速诊断胎儿染色体数目异常的价值。方法 对248例孕18～24周，具有产前诊断指征者，在B超引导下经腹抽取249例羊水后，应用特异性探针对未经过培养的羊水间期细胞进行荧光原位杂交。结果 共检出染色体数目异常6例，异常率为2.4%。异常类型包括21三体，13三体，XO和嵌合型XO，以及XXX。21三体占全部异常的33.3%。其中，B超畸形提示异常诊断率最高，唐氏筛查高风险为指征的诊断异常率次之。孕妇年龄大于35岁组中诊断的染色体数目异常率低于年龄组小于35岁。怀孕次数1次、2次和3次组中分别有3例、1例和2例染色体数目异常胎儿。生产次数分为0次和1次的组别中各有3例异常核型胎儿。结论 FISH技术用于羊水细胞13、18、21、X,Y染色体数目检查时具有快速、准确的特点，可以用于比例高的嵌合细胞的检测。血性羊水细胞可以进行FISH检测。
Objective To investigate the efficiency of detection of chromosome aneuploidy in uncultured amniotic fluid samples by FISH, discuss the importance of FISH in rapid prenatal diagnosis, and pay attention to the effect of maternal blood containminant in detection. Method The interphase nuclei of amniotic fluid from 248 women at 18-24 weeks pf pregnancy were detected by chromose-specific DNA probe using FISH. Results 2 fetuses with trisomy 21 syndrome, 1 fetuses with trisomy 13 syndrome, 1 fetuses with XO, 1 fetuses with XO/XX, 1 fetuses with XXX syndrome were identified. The coincidence rate of diagnosis between FISH and conventional cytogenetics was 100%. The aneuploidy rate was highest in the group with abnormality in USD. The aneuploidy rate was higher in group MA<35 than group MA>35. There were 3 cases, 1case and 2 cases aneuploidy in different gestation groups. Both the parity group had the same cases aneuploidy. Conclussions FISH is fast, specific and sensitive. Some kind of mosaics aneuploidy type can be detected by FISH. Most of the aminotic fluid with maternal contaiminant (blood) still can be detected by FISH with the same result of cytogenetics. The detection rate of FISH in different lab was little similar, with the various protocol according to the equipment.
