5 756例孕妇外周血胎儿游离DNA无创产前筛查结果分析

目的：探讨无创产前基因检测（non-invasive prenatal testing，NIPT）技术在胎儿染色体非整倍体疾病筛查中的应用价值。方法：选择2014年12月-2016年12月于中国人民解放军第202医院行NIPT的孕妇5 756例，NIPT高风险的孕妇建议行羊膜腔穿刺及胎儿染色体核型分析，并对检测结果进行分析。结果：5 756例孕妇中NIPT提示高风险62例，阳性率为1.08%。其中48例孕妇行染色体核型分析，确诊21-三体24例、18-三体2例、13-三体1例、性染色体异常8例，阳性预测值分别为86%、40%、25%和73%。行NIPT的孕妇中，高龄、无明确指征坚持行NIPT及血清学筛查临界风险的孕妇所占比例较高，分别为37.70%、32.35%和16.09%。超声软指标异常组NIPT阳性率高于其他组，差异有统计学意义（P＜0.01）。结论：NIPT对21、18、13-三体和性染色体异常具有较高的检出率，对21-三体和性染色体异常具有较高的阳性预测值。NIPT被高龄、无明确指征坚持行NIPT及血清学筛查临界风险的孕妇广泛接受，可大量减少侵入性产前诊断操作，具有较好的临床应用前景。

5 756 Cases Analysis of Non-Invasive Prenatal Fetal Free-DNA Testing in Peripheral Serum of Pregnant Women

Objective：To evaluate the clinical application of non-invasive prenatal testing (NIPT) in screening of fetal chromosomal aneuploidy. Methods：Totally 5 756 pregnant women receiving NIPT in People′s Liberation Army No.202 Hospital from December 2014 to December 2016 were retrospectively analyzed. Amniocentesis and fetal karyotyping were recommended in those women with the high-risk results of NIPT. Results：Among 5 756 pregnant women, 62 cases were found the high-risk by NIPT, with a positive rate of 1.08%. 48 cases underwent chromosome karyotype analysis, including 24 cases with trisomy 21, 2 cases with trisomy 18, 1 case with trisomy 13, and 8 cases with sex chromosome abnormality. The positive predictive values of trisomy 21, trisomy 18, trisomy 13 and sex chromosome number abnormality were 86%, 40%, 25% and 73%, respectively. Among those pregnant women receiving NIPT, the three proportions of pregnant women with advanced age, low-risk but asking for NIPT and critical risk in their serum screening were 37.70%, 32.35% and 16.09%, respectively. The positive rate of NIPT in those women with abnormal ultrasonic soft index was statistically higher than that in others (P＜0.01). Conclusions：NIPT has high detection rates of trisomy 21, trisomy 13, trisomy 18 and sex chromosome abnormalities. It has high positive predictive values of trisomy 21 and sex chromosome number abnormality. NIPT has been widely accepted by those pregnant women with advanced age, low-risk but asking for NIPT and critical risk in serum screening. NIPT has a good clinical prospect because NIPT can greatly reduce the invasive prenatal diagnosis.