1258例孕妇孕中期羊水细胞染色体核型分析

Karyotype analysis of amniotic fluid cells in 1258 pregnant women in the second trimester

目的以孕妇孕中期羊水细胞染色体核型为研究对象,检测不同指标引起染色体核型异常的发生率。方法选取近5年来我院遗传咨询门诊就诊需行羊膜腔穿刺术的孕妇1258例,进行羊水细胞染色体核型诊断,分析不同检查指标下出现异常核型的发生率。24例核型异常胎儿的父母进行外周血淋巴细胞核型分析。结果 1258份羊水细胞染色体核型中检出异常染色体核型56例,异常检出率为4.45%。其中染色体数目异常33例,结构异常23例(包括9号染色体臂内或臂间倒位10例)。56例异常核型中最常见的为21三体,17例21三体中由于高龄引起的有7例。结论对唐氏筛查或无创DNA筛查提示高风险、高龄、超声异常及不良孕产史等指征的孕妇应该进行羊水细胞染色体核型分析,可有效避免染色体异常患儿出生。

Objective:The chromosome karyotype of amniotic fluid cells in the seco-nd trimester of pregnancy was studied,To detect the incidence of chromosome karyotype abnormality caused by different indicators. Methods:A total of 1258 preg-nant women who needed amniocentesis in the outpatient department of genetic counseling in our hospital in the past 5 years were selected for diagnosis of chromosome karyotype of amniotic fluid cells,and the incidence of abnormal karyotype was analyzed under different examination indexes. The parents of 24 fetuses with abnormal karyotype underwent peripheral blood lymphocyte karyotype analysis. Results:Abnormal karyotypes were detected in 56 cases of 1258 amniotic fluid cell karyotypes,with an abnormal detection rate of 4.45%.Among them,there were 33 cases of abnormal chromosome number and 23 cases of abnormal structure(including 10 cases of intra-arm or inter-arm inversion of chromosome 9). Among the 56 cases of abnormal karyotypes,the most common one was 21 trisomy,and among the 17 cases of 21 trisomy,7 cases were caused by old age. Conclusion:Somatic karyotype analysis of amniotic fluid cells should be carried out for pregnant women with down′s screening or non-invasive DNA screening that indicates high risk,advanced age,ultrasonic abnormality and poor pregnancy and birth history,so as to effectively avoid the birth of children with chromosomal abnormality.