胎儿超声及染色体产前诊断对唐氏综合征产前筛查为临界风险的临床价值

Clinical value of fetal ultrasonography and prenatal diagnosis of chromosomal abnormalities for critical-risk pregnancies of Down syndrome

目的探讨中孕期唐氏综合征筛查为临界风险的胎儿超声及染色体检查的临床意义。方法回顾性分析中孕期唐氏综合征产前筛查临界风险的2 281例胎儿超声检查结果,以低风险2 500例为对照,比较两组单发软指标、多发软指标、单发畸形、多发畸形等异常检出率。并分析其中1 332例知情选择羊膜腔穿刺术者胎儿染色体产前诊断结果。结果 1临界风险组胎儿超声检查检出单发软指标异常696例(30.51%)、多发软指标异常118例(5.17%)、单发畸形18例(0.79%)、多发畸形7例(0.31%)。低风险组检出单发软指标异常308例(12.32%)、多发软指标异常82例(3.28%)、单发畸形5例(0.20%)、多发畸形1例(0.04%)。临界风险组各项异常检出率明显高于低风险组(P<0.05,P<0.01)。2选择羊膜腔穿刺术胎儿染色体产前诊断1 332例临界风险组中,合并单发软指标异常135例,多发软指标异常83例,单发畸形11例,多发畸形5例者胎儿染色体检查结果均正常。31 332例临界风险组中检出常染色体结构异常10例,性染色体结构异常1例。异常检出率0.08%。其中,染色体平衡易位7例,臂间倒位3例,等臂染色体1例。9例系母系或父系来源,2例为新发突变。11例染色体结构异常的胎儿超声检查均无明显异常发现。结论胎儿超声检查能为唐氏综合征临界风险孕妇的遗传咨询提供有价值的信息;唐氏综合征临界风险亦提示胎儿染色体结构异常风险增加。

Objective To investigate the clinical significances of fetal ultrasound examination and prenatal diagnosis of fetal chromosome abnormality for critical-risk pregnancies of Down syndrome （ DS ） in second trimester. Methods A retrospectively study was carried out on 2 281 pregnancies with critical-risk DS and on 2 500 low-risk cases admitted in our center from January 1, 2012 to March 15, 2016. Fetal uhrasonography was performed on all the 4 78l cases for the detection rates of single uhrasonographic soft markers, multiple uhrasonographic soft markers, single malformations, multiple malformations and other abnormalities. The results were compared between the 2 groups. Among those with critical-risk DS, 1 332 cases who were aware of the situation accepted choose amniocentesis for prenatal diagnosis of fetal chromosomal abnormalities. Results （1） Fetal ultrasound examination detected 696 cases （30.51%） of single uhrasonographic soft markers, 118 cases （5. 17% ） of multiple uhrasonographie soft markers, 18 eases （0.79%） of single malformation, and 7 cases （0.31%） multiple malformations in the critical-risk group. But for the low-risk group, the above indicators were 308 eases （ 12.32% ）, 82 eases （3.28%）, 5 eases （0.20%） , and 1 case （0.04%）. The abnormal detection rates were significantly higher in the former than the latter group （P 〈 0.05）. （2）Amniocentesis indicated that among the 1 332 cases from critical-risk group, there were 135 cases complicated with single ultrasonographic soft markers, 83 cases with multiple uhrasonographic soft markers, and 11 cases with single malformation. The 5 cases of multiple malformations had normal fetal chromosomal results. （3）The abnormal rate of chromosome was 0.08% （11 cases） , including 10 cases of autosomal and 1 of sex chromosomealstructural abnormalities. Among them, 7 cases were chromosome balanced translocation, 3 cases inversion, and 1 case arm chromosome. Nine cases of maternal or paternal origins, and 2 cases of de novo mutations. Conclusion Fetal ultrasound examination can provide valuable information of genetic counseling for critical-risk DS pregnancies. Critical-risk DS also indicates increased risk of fetal chromosomal structure abnormalities.