无创产前基因检测筛查胎儿染色体非整倍体疾病结果分析

目的 分析孕妇外周血胎儿游离DNA无创产前基因检测(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 选取2020年于本院接受NIPT孕妇6 370例,分析不同年龄段、孕周的孕妇染色体异常风险情况,统计与羊水细胞染色体核型分析结果的符合情况。结果 6 370例孕妇中,共筛查出染色体异常高风险90例(1.41%),其中21-三体综合征22例(0.35%)、18-三体综合征12例(0.19%)、13-三体综合征高风险8例(0.13%)、性染色体异常高风险26例(0.41%)、其他常染色体异常高风险22例(0.35%)。年龄≥35岁孕妇染色体异常高风险率(2.71%)高于＜30岁组(0.98%)和30～34岁组(1.36%),差异有统计学意义(χ2=18.727, P＜0.01)。孕周≤12周的染色体异常高风险率为10.00%, 13～20周组为1.18%, 21～28周组为2.64%,差异有统计学意义 (χ2=17.596,P＜0.01)。66例NIPT高风险孕妇进行了羊水细胞染色体核型分析,诊断结果阳性31例(46.97%),其中21-三体综合征阳性预测值为87.50%、18-三体综合征为88.89%、13-三体综合征为0%、性染色体异常为50.00%、其他常染色体异常为0%。结论 NIPT对21-三体综合征、18-三体综合征具有较高的检测价值。但对于13-三体、性染色体、以及其他染色体异常的阳性预测值较低。NIPT可以作为胎儿染色体疾病的主要筛查手段,测序结果为高风险孕妇仍需行羊水/脐血穿刺,以有效地避免染色体异常患儿的出生。

Analysis of results of screening fetal chromosomal aneuploidy by noninvasive prenatal gene detection

Objective To analyze the application value of noninvasive prenatal testing (NIPT) in fetal chromosome aneuploidy screening. Methods A total of 6 370 pregnant women who received NIPT in Xuzhou Maternity and Child Health Care Hospital from January 2020 to December 2020 were selected to analyze the risk of chromosomal abnormalities in pregnant women of different ages and gestational weeks, and the consistent of the results of karyotype analysis of NIPT and amniotic fluid cells were compared. Results Of the 6 370 pregnant women, 90 cases (1.41%) were found to be at high risk of chromosomal abnormalities, of which, 22 cases of 21-trisomy syndrome (0.35%), 12 cases of 18-trisomy syndrome (0.19%), 8 cases of 13-trisomy syndrome (0.13%), 26 cases of sex chromosome abnormality (0.41%), and 22 cases of other autosomal abnormalities (0.35%) were found. In terms of the age of pregnant women, the risk of chromosomal abnormalities in pregnant women aged ≥35 years (2.71%) was significantly higher than those in pregnant women aged<30 years (0.98%) and 30-34 years (1.36%), and the difference was statistically significant (χ2=18.727, P<0.01). There was a statistically significant difference (χ2=17.596, P<0.01) among gestational weeks of ≤ 12 weeks (10.00%), 13-20 weeks (1.18%), and 21-28 weeks (2.64%). The karyotype analysis of amniotic fluid cells was carried out in 66 high-risk pregnant women with NIPT. The diagnostic results were positive in 31 cases (46.97%), of which, the positive predictive value of 21-trisomy syndrome was 87.50%, 18-trisomy syndrome was 88.89%, 13-trisomy syndrome was 0%, sex chromosome abnormality was 50.00%, and other autosomal abnormalities were 0%. Conclusion NIPT has high detection value for 21-trisomy syndrome and 18-trisomy syndrome, however, NIPT’s positive predictive value for 13-trisomy syndrome, sex chromosome, and other chromosomal abnormalities were low. NIPT can be used as the main screening method for fetal chromosome aneuploidy screening. The pregnant women with high risk of chromosomal aneuploidy still need amniotic fluid/umbilical blood puncture to effectively avoid the birth of children with chromosomal abnormalities.