胎儿颈项透明层增厚与胎儿染色体异常的关联性研究

Analysis on relevance between fetal nuchal translucency and chromosome abnormality

目的探讨胎儿NT异常与染色体异常的关系。方法对我院产前超声NT筛查并行羊水穿刺产前诊断的566病例分为NT正常组和NT异常组,分析并比较两组染色体异常的比例。将NT增厚的病例又分为轻度增厚组和明显增厚组,比较两组的染色体异常的比例。结果 566例中NT正常355例和NT异常211例,NT正常组中有21例合并染色体异常,比例为5.9%,包括染色体非整倍体16例,分别为21三体14例,18三体1例,性染色体异常1例;染色体结构异常5例。NT异常组中有39例合并染色体异常,比例为18.5%,包括染色体非整倍体30例,分别为21三体21例,18三体6例,性染色体异常3例;染色体结构异常9例。比较两组的染色体异常比例,其中NT正常组的染色体异常比例明显低于NT异常组,差异有统计学差异(P<0.05)。211例NT异常包括轻度异常112例和明显异常99例,轻度异常组中染色体异常比例为10.7%,明显异常组的染色体异常比例为27.3%,两者比较差异有统计学差异(P<0.05)。结论胎儿合并NT增厚常合并染色体异常,染色体异常以非整倍体为主,其中21三体最常见,NT筛查是产前筛查的有效方法。

Objective To evaluate the relevance between fetal nuchal translucency and chromosome abnormality. Methods 566 cases of pregnancies with fetal nuchal translucency measurement were divided into normal NT group and abnormal NT group. The abnormal NT group was divided into mild thickened NT group and severe thickened NT group. The abnormal chromosome incidence of each group was analyzed. Results 566 cases includes 355 cases with normal NT and 211 cases with abnormal NT. 21 cases（ 5. 9%） in normal NT group were complicated with abnormal fetal chromosome,including 14 cases of trisomy 21,one case of trisomy 18 and one case of abnormal sex chromosome. 39 cases（ 18. 5%） in abnormal NT group were complicated with abnormal fetal chromosome,including 21 cases of trisomy 21,six cases of trisomy 18 and three cases of abnormal sex chromosome. The abnormal chromosome incidence of abnormal NT group was significantly higher than that of normal NT group（ P 0. 05）. 211 cases of abnormal NT group included 112 cases in mild thickened NT group and 99 cases in severe thickened NT group. The abnormal chromosome incidence of severe thickened NT group（ 27. 3%） was significantly higher than that of normal NT group（ 10. 7%）（ P 0. 05）. Conclusions Fetuses with thickened NT are highly relevant with fetal chromosomal abnormalities. Aneuploid is the common chromosome abnormalities in fetuses with abnormal NT. NT is a useful marker in prenatal screening.